more than 2 Z-Endstops not homing with Marlin on Octopus 1.1

[tu77]

recently I did upgrade my DIY CoreXY Printer with a 3rd Z axis.

i figured that all 3 motors are functioning correctly and all end switches get triggered as supposed.

I don't use a Z-Probe, the Print bed gets leveled on 3 points by the 3 Z-dives (that was the plan)

The Behavior:

• all 3 axis are moving normal before homing,
• X and Y axis home normally
• If I home the Z axis, all 3 axis are moving towards the end switches as usually
• the switches get triggered and the print bed gets even leveled (this is visible)
• Z moves away form the switches a bit and moves than back to the trigger point witch is usually the "0"
• in this moment the printer gets halted "Homing Failed" "Printer halted. kill"

at the moment I downgraded to 2 Z axis again.. very disappointing ..
With 2 Z Axis it`s working fine.

attached you find the configuration files..

My setup:
BTT Octopus 1.1 + TFT50

TMC2208 drivers for Z + Extr.
TMC2209 drivers for X+Y
Marlin 2.1.2.1 same problem with Latest 2.1.x with Hotfixes
no Z-Probe, no BLtouch
each Z motor has its own driver and are moving freely

the major changes i made for the 3rd Z axis:
Configuration.h.:
#define Z3_DRIVER_TYPE TMC2208 // 3. Z Achse
#define USE_XMAX_PLUG
#define USE_YMAX_PLUG_

Configuration_adv.h:
#define Z_MULTI_ENDSTOPS

pins_BTT_OCTOPUS_V1_common.h:
#define FIL_RUNOUT_PIN PG14
//#define FIL_RUNOUT2_PIN PG13
//#define FIL_RUNOUT3_PIN PG14
#define FIL_RUNOUT4_PIN PG15

Conclusion:
The homing works correctly but if the Z Axis moves to the Z"0" after homing something strange happens

Configuration.h.txt
Configuration_adv.h.txt
pins_BTT_OCTOPUS_V1_common.h.txt