When using a constraint to disable collision between the constrained bodies, collisions are not ignored if the constraint is part of a streamed in sub level that does not block on load. This also occurs for AlwaysLoaded sub levels.

Steps to Reproduce

Create an actor BP with two colliding simulating bodies and a constraint between them set to disable collision.

Place an instance in a parent level and sub level.


Set the sub level streaming method to Blueprint, and load the level on begin play.

Result: Collision between the overlapping bodies is ignored.


Set the sub level streaming method to AlwaysLoaded and play.

Result: Collisions between the overlapping bodies of the sub level instance are not ignored.

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ComponentUE - Simulation - Physics
Affects Versions4.204.23
Target Fix4.27
CreatedSep 5, 2019
ResolvedNov 19, 2020
UpdatedDec 2, 2020