MASS / SetCustomDataFloat resets itself. UE5.5.4

Goal: I am trying to use PerInstanceCustomData to drive material color variations using the standard MassSpawner and DataAsset.

The Problem: Mass resets CustomDataFloats to 0 upon spawning entities. It appears to override or ignore values set in both Blueprints and C++.

What I’ve Tried:

  • Setting the value on spawn (ignored/reset to 0).

  • Forcing the float values during Tick (Mass seems to treat them as unnecessary and removes them again).

Question: Do I need a specific Mass Processor to persist these values? Or is there a specific setting in the DataAsset required to keep Custom Data from being culled?