Quick answer: Unreal physics asset's collision channels reset to defaults on per-instance spawn? CDO defaults override; set channels per-instance in BeginPlay.
Custom physics asset with combat channel; spawned actors all use Pawn channel.
Set channels in BeginPlay
Per-actor; apply the combat channel. Spawned instances correct.
Or override in DT
Data Table with per-asset overrides. Lookup at spawn.
Audit per spawned type
Each spawn type's channels. Defaults vs intended.
“Per-instance overrides need explicit application. CDO defaults are the trap.”
If your spawn flow shows default behavior, the per-instance override is the bug source.