Hidden Realm and Operation: Starcleave prevent swimming (independently)

[unilock]

Mod Name

Hidden Realm

Mod Homepage

https://modrinth.com/mod/hidden-realm

Minecraft version

1.21.1

Describe the bug

With Hidden Realm or Operation: Starcleave installed, the player is unable to swim in water - all movement controls do nothing (unless the player is flying (as in creative mode), in which the player can fly through the fluid as normal). Lava at least allows the player to move, but not swim upwards.

Steps to reproduce

1. Install NeoForge, Sinytra Connector, Forgified Fabric API
2. Install Hidden Realm and its dependencies
3. Start the game and join a world
4. Try to swim in water. You cannot.

Logs

latest.log: https://gist.github.com/unilock/3d07bb8fe4ddb1848737d25bc9b56684

Additional context

This issue also occurs with Operation: Starcleave (specifically, my fork of it).

[unilock]

Appears to be the same issue as #1343, #1431, #1499, and #1502.
Something is very wrong...!