The process of performing SetTextureParameterValue on a decal component during BeginPlay, the result will not be the same every time when streaming a level.

If executing CreateDynamicMaterialInstance and SetTextureParameterValue on BeginPlay for the decal component, the decal will be different the first and second time level streaming.

1. Open the attached project in editor.
2. Play in editor in ThirdPersonMap level.
3. The player moves forward and the level streaming of the World Partition is generated to display the Actor with the decal component.

1. The player moves backward and then moves forward again to generate level streaming to confirm the decal. At this time, the decal has changed from the first streaming and there appears to be no texture assignment.

(See attached gif for step3,4)

 The following log is output on the second level streaming. 

LogMaterial: Warning: MaterialInstanceDynamic /Memory/UEDPIE_0_ThirdPersonMap_MainGrid_L0_X8_Y3_DL0.ThirdPersonMap:PersistentLevel.BP_TestObject_C_UAID_9C7BEF4D27D9D22401_1118863137.Decal.MaterialInstanceDynamic_0 is not a valid parent for MaterialInstanceDynamic /Memory/UEDPIE_0_ThirdPersonMap_MainGrid_L0_X8_Y3_DL0.ThirdPersonMap:PersistentLevel.BP_TestObject_C_UAID_9C7BEF4D27D9D22401_1118863137.Decal.MaterialInstanceDynamic_1. Only Materials and MaterialInstanceConstants are valid parents for a material instance. Outer is Decal