Pretty simple one that caused me a minor mental breakdown and sidetracked troubleshooting an MMU for about a day:
RRF ver 3.5.0rc2 with DWC 3.5.0rc2, try using M574 to set an endstop on the "V" axis and you will find the endstop in the object model will populate (ie not null) but the data is incorrect. "high end" remains false regardless of what you set and the type will always be "unknown" when it should just be inputpin. M574 command correctly reports the data so not sure what is going wrong in DWC...