Hi, thank you for your answer
That what is strange for me is that the World->LineTraceSingleByObjectType (also called from AsyncPhysicsTickComponent) works without triggering this ensure.
As I am able to optimize this line trace by limiting possible objects to few that overlaps my actor, I changed my code to do few quick LineTraceComponent instead of one slow LineTraceSingleByObjectType that runs over whole BVH tree for whole scene.
And generally it works, performance is much better - I do not found any issues so far.
Only this ensure related to thread makes me nervous 
So I am not sure what to do - probably I’ll left it as is, because it works, but I am aware ignoring such warnings means problem “somewhere, sometime”.
For my purpose AsyncLineTraceByChannel doesn’t look good - I need this trace to be performed “ByComponent”, to make use of my short list of possible compoments to trace.