I think i solved this problem, at least for me, my issue was: the character moves his arms according to Mouse position, in Viewport/PIE works fine, but when running in Standalone it just didn’t work, my solution was place my Character_BP inside the map as reference for gamemode, not only Player Start, i place my Character in the scene, and it solved the problem!
it seems there are some deep relations between gamemode and something else. when the character gets spawned, it’s BP doesn’t run the same after packaging