diff --git a/.github/workflows/build-test.yml b/.github/workflows/build-test.yml
index fd6a1b212..0ae656e33 100644
--- a/.github/workflows/build-test.yml
+++ b/.github/workflows/build-test.yml
@@ -10,6 +10,9 @@ on:
       coverage:
         type: string
         default: "OFF"
+      dev_mode:
+        type: string
+        default: "OFF"
       lib_msg_delivery:
         type: string
         default: "OFF"
@@ -40,6 +43,12 @@ on:
         type: string
         description: "Ubuntu version to use, e.g. '20.04'"
         default: "latest"
+      verbose_test_output:
+        type: string
+        default: "OFF"
+      verbose_make_output:
+        type: string
+        default: "ON"
     secrets:
       CODECOV_TOKEN:
         description: "Codecov repo token"
@@ -83,6 +92,12 @@ jobs:
           if [[ "${{ inputs.coverage }}" == "ON" ]]; then
             flags="$flags -DNATS_COVERAGE=ON"
           fi
+          if [[ "${{ inputs.dev_mode }}" == "ON" ]]; then
+            flags="$flags -DDEV_MODE=ON"
+          fi
+          if [[ "${{ inputs.verbose_make_output }}" == "ON" ]]; then
+            flags="$flags -DCMAKE_VERBOSE_MAKEFILE=ON"
+          fi
           echo "flags=$flags" >> $GITHUB_OUTPUT
 
       - id: nats-vars
@@ -158,11 +173,7 @@ jobs:
           export PATH=../deps/nats-server:../deps/nats-streaming-server:$PATH
           export NATS_TEST_SERVER_VERSION="$(nats-server -v)"
           flags=""
-          ctest --timeout 60 --output-on-failure --repeat-until-fail ${{ inputs.repeat }} 2>&1 | tee /tmp/out.txt
-          if [[ $(grep -q 'ThreadSanitizer: ' /tmp/out.txt; echo $?) == 0 ]]; then
-            echo "!!! ThreadSanitizer detected WARNING(s) !!!"
-            exit 1
-          fi
+          ctest --timeout 60 --output-on-failure --repeat-until-fail ${{ inputs.repeat }}
 
       - name: Upload coverage reports to Codecov
         # PRs from external contributors fail: https://github.com/codecov/feedback/issues/301
diff --git a/.github/workflows/on-pr-debug.yml b/.github/workflows/on-pr-debug.yml
index eccc0f9f2..089cd7f58 100644
--- a/.github/workflows/on-pr-debug.yml
+++ b/.github/workflows/on-pr-debug.yml
@@ -28,36 +28,51 @@ jobs:
     secrets:
       CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
 
-  sanitize-addr:
-    name: "Sanitize address"
+  coverage-pooled:
+    name: "Coverage"
     uses: ./.github/workflows/build-test.yml
     with:
-      sanitize: address
+      coverage: ON
       server_version: main
       type: Debug
+      lib_msg_delivery: ON
+    secrets:
+      CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
 
-  sanitize-addr-lib-msg-delivery:
-    name: "Sanitize address (lib_msg_delivery)"
+  dev-mode:
+    name: "DEV_MODE"
     uses: ./.github/workflows/build-test.yml
     with:
-      sanitize: address
+      dev_mode: ON
       server_version: main
-      lib_msg_delivery: ON
+      type: Debug
+      verbose_test_output: ON
+      verbose_make_output: ON
 
-  san-addr:
-    name: "Sanitize address (lib_write_deadline)"
+  sanitize:
+    name: "Sanitize"
+    strategy:
+      fail-fast: false
+      matrix:
+        compiler: [gcc, clang]
+        sanitize: [address, thread]
+        pooled_delivery: [ON, OFF]
     uses: ./.github/workflows/build-test.yml
     with:
-      sanitize: address
       server_version: main
-      lib_write_deadline: ON
+      type: Debug
+      compiler: ${{ matrix.compiler }}
+      sanitize: ${{ matrix.sanitize }}
+      lib_msg_delivery: ${{ matrix.pooled_delivery }}
 
-  san-thread:
-    name: "Sanitize thread"
+  san-addr-deadline:
+    name: "Sanitize address (lib_write_deadline)"
     uses: ./.github/workflows/build-test.yml
     with:
-      sanitize: thread
+      type: Debug
+      sanitize: address
       server_version: main
+      lib_write_deadline: ON
 
   Windows:
     name: "Windows"
diff --git a/.github/workflows/on-push-release.yml b/.github/workflows/on-push-release.yml
index d47c20308..50513575c 100644
--- a/.github/workflows/on-push-release.yml
+++ b/.github/workflows/on-push-release.yml
@@ -22,3 +22,26 @@ jobs:
       server_version: main
       ubuntu_version: ${{ matrix.ubuntu_version }}
       compiler: ${{ matrix.compiler }}
+
+  dev-mode:
+    name: "DEV_MODE"
+    uses: ./.github/workflows/build-test.yml
+    with:
+      dev_mode: ON
+      server_version: main
+      verbose_test_output: ON
+      verbose_make_output: ON
+
+  sanitize-addr:
+    name: "Sanitize address"
+    uses: ./.github/workflows/build-test.yml
+    with:
+      sanitize: address
+      server_version: main
+
+  san-thread:
+    name: "Sanitize thread"
+    uses: ./.github/workflows/build-test.yml
+    with:
+      sanitize: thread
+      server_version: main
diff --git a/src/conn.c b/src/conn.c
index 1b405c852..7cfe9beb1 100644
--- a/src/conn.c
+++ b/src/conn.c
@@ -1137,17 +1137,29 @@ _resendSubscriptions(natsConnection *nc)
 
         adjustedMax = 0;
         natsSub_Lock(sub);
+        if (sub->libDlvWorker != NULL)
+        {
+            natsMutex_Lock(sub->libDlvWorker->lock);
+        }
         // If JS ordered consumer, trigger a reset. Don't check the error
         // condition here. If there is a failure, it will be retried
         // at the next HB interval.
         if ((sub->jsi != NULL) && (sub->jsi->ordered))
         {
             jsSub_resetOrderedConsumer(sub, sub->jsi->sseq+1);
+            if (sub->libDlvWorker != NULL)
+            {
+                natsMutex_Unlock(sub->libDlvWorker->lock);
+            }
             natsSub_Unlock(sub);
             continue;
         }
         if (natsSub_drainStarted(sub))
         {
+            if (sub->libDlvWorker != NULL)
+            {
+                natsMutex_Unlock(sub->libDlvWorker->lock);
+            }
             natsSub_Unlock(sub);
             continue;
         }
@@ -1160,6 +1172,10 @@ _resendSubscriptions(natsConnection *nc)
             // messages have reached the max, if so, unsubscribe.
             if (adjustedMax == 0)
             {
+                if (sub->libDlvWorker != NULL)
+                {
+                    natsMutex_Unlock(sub->libDlvWorker->lock);
+                }
                 natsSub_Unlock(sub);
                 s = natsConn_sendUnsubProto(nc, sub->sid, 0);
                 continue;
@@ -1172,6 +1188,10 @@ _resendSubscriptions(natsConnection *nc)
 
         // Hold the lock up to that point so we are sure not to resend
         // any SUB/UNSUB for a subscription that is in draining mode.
+        if (sub->libDlvWorker != NULL)
+        {
+            natsMutex_Unlock(sub->libDlvWorker->lock);
+        }
         natsSub_Unlock(sub);
     }
 
@@ -3435,7 +3455,7 @@ natsConnection_Reconnect(natsConnection *nc)
         return nats_setDefaultError(NATS_CONNECTION_CLOSED);
     }
 
-    natsSock_Close(nc->sockCtx.fd);
+    natsSock_Shutdown(nc->sockCtx.fd);
 
     natsConn_Unlock(nc);
     return NATS_OK;
diff --git a/src/js.c b/src/js.c
index e31dd2f0a..3d3e4bb18 100644
--- a/src/js.c
+++ b/src/js.c
@@ -2045,6 +2045,10 @@ _hbTimerFired(natsTimer *timer, void* closure)
     natsStatus          s    = NATS_OK;
 
     natsSub_Lock(sub);
+    if (sub->libDlvWorker != NULL)
+    {
+        natsMutex_Lock(sub->libDlvWorker->lock);
+    }
     alert = !jsi->active;
     oc = jsi->ordered;
     jsi->active = false;
@@ -2062,10 +2066,18 @@ _hbTimerFired(natsTimer *timer, void* closure)
             natsCondition_Signal(sub->cond);
             natsTimer_Stop(timer);
         }
+        if (sub->libDlvWorker != NULL)
+        {
+            natsMutex_Unlock(sub->libDlvWorker->lock);
+        }
         natsSub_Unlock(sub);
         return;
     }
     nc = sub->conn;
+    if (sub->libDlvWorker != NULL)
+    {
+        natsMutex_Unlock(sub->libDlvWorker->lock);
+    }
     natsSub_Unlock(sub);
 
     if (!alert)
@@ -2075,12 +2087,20 @@ _hbTimerFired(natsTimer *timer, void* closure)
     if (oc)
     {
         natsSub_Lock(sub);
+        if (sub->libDlvWorker != NULL)
+        {
+            natsMutex_Lock(sub->libDlvWorker->lock);
+        }
         if (!sub->closed)
         {
             // If we fail in that call, we will report to async err callback
             // (if one is specified).
             s = jsSub_resetOrderedConsumer(sub, sub->jsi->sseq+1);
         }
+        if (sub->libDlvWorker != NULL)
+        {
+            natsMutex_Unlock(sub->libDlvWorker->lock);
+        }
         natsSub_Unlock(sub);
     }
 
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 58a4aa14f..c15ccfc62 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -35,7 +35,6 @@ file(STRINGS list.txt listOfTestNames)
 
 # For each test name
 foreach(name ${listOfTestNames})
-
   # Create a test and pass the index (start and end are the same)
   # to the testsuite executable
   add_test(NAME Test_${name}
@@ -45,6 +44,12 @@ foreach(name ${listOfTestNames})
   # Make sure the test passes
   set_tests_properties(Test_${name} PROPERTIES PASS_REGULAR_EXPRESSION "ALL PASSED")
 
+  # Set TSAN_OPTIONS for the test
+  if(NATS_SANITIZE)
+    set_tests_properties(Test_${name} PROPERTIES
+           ENVIRONMENT "TSAN_OPTIONS=detect_deadlocks=1:second_deadlock_stack=1:halt_on_error=1:report_signal_unsafe=1")
+  endif(NATS_SANITIZE)
+
   # Bump the test index number
   math(EXPR testIndex "${testIndex}+1")
 endforeach()
diff --git a/test/test.c b/test/test.c
index a2c898038..12a92c4d5 100644
--- a/test/test.c
+++ b/test/test.c
@@ -5477,6 +5477,7 @@ test_natsSrvVersionAtLeast(void)
             {
                 s = NATS_ERR;
             }
+            natsConn_Unlock(nc);
         }
     }
     testCond(s == NATS_OK);
@@ -13337,7 +13338,10 @@ test_ClientAutoUnsubAndReconnect(void)
     nats_Sleep(10);
 
     test("Received no more than max: ");
-    testCond((s == NATS_OK) && (arg.sum == 10));
+    natsMutex_Lock(arg.m);
+    int sum = arg.sum;
+    natsMutex_Unlock(arg.m);
+    testCond((s == NATS_OK) && (sum == 10));
 
     natsSubscription_Destroy(sub);
     natsConnection_Destroy(nc);
@@ -13390,6 +13394,7 @@ test_AutoUnsubNoUnsubOnDestroy(void)
     natsMutex_Lock(arg.m);
     while ((s != NATS_TIMEOUT) && !arg.done)
         s = natsCondition_TimedWait(arg.c, arg.m, 2000);
+    natsMutex_Unlock(arg.m);
     testCond(s == NATS_OK);
 
     natsConnection_Destroy(nc);
@@ -20252,6 +20257,7 @@ test_ForcedReconnect(void)
     CHECK_SERVER_STARTED(pid);
     IFOK(s, natsOptions_Create(&opts));
     IFOK(s, natsOptions_SetReconnectedCB(opts, _reconnectedCb, &arg));
+    IFOK(s, natsOptions_SetReconnectWait(opts, 100));
     IFOK(s, natsConnection_Connect(&nc, opts));
     IFOK(s, natsConnection_SubscribeSync(&sub, nc, "foo"));
     testCond(s == NATS_OK);
@@ -20800,6 +20806,7 @@ test_EventLoop(void)
     natsMutex_Lock(arg.m);
     if (arg.attached != 2 || !arg.detached)
         s = NATS_ERR;
+    natsMutex_Unlock(arg.m);
     testCond(s == NATS_OK);
 
     natsSubscription_Destroy(sub);
@@ -29485,6 +29492,9 @@ _jsOrderedErrHandler(natsConnection *nc, natsSubscription *subscription, natsSta
 {
     struct threadArg    *args = (struct threadArg*) closure;
 
+    if (err != NATS_MISSED_HEARTBEAT)
+        return;
+
     natsMutex_Lock(args->m);
     args->status = err;
     natsCondition_Signal(args->c);
@@ -29824,6 +29834,7 @@ test_JetStreamOrderedConsSrvRestart(void)
     natsMutex_Lock(args.m);
     while ((s != NATS_TIMEOUT) && !args.reconnected)
         s = natsCondition_TimedWait(args.c, args.m, 2000);
+    natsMutex_Unlock(args.m);
     testCond(s == NATS_OK);
 
     test("Send 1 message: ");
@@ -33921,8 +33932,8 @@ test_MicroAsyncErrorHandler_MaxPendingMsgs(void)
     natsMutex_Lock(arg.m);
     while ((s != NATS_TIMEOUT) && !arg.closed)
         s = natsCondition_TimedWait(arg.c, arg.m, 1000);
-    natsMutex_Unlock(arg.m);
     testCond((s == NATS_OK) && arg.closed && (arg.status == NATS_SLOW_CONSUMER));
+    natsMutex_Unlock(arg.m);
 
     microService_Destroy(m);
     _waitForMicroservicesAllDone(&arg);