Thought that I was experiencing same issue, but after trying to reproduce in clean project, I finally remembered a way of testing what’s affecting your physics object blueprint. Try this and look into log. Look for unexpected actor names and too big impulse normal coordinates (like more than 100. Around 15-40 is a “lying still” impulse for active physics object lying on the floor).
Maybe some collision checkbox or preset gone crazy, or collision on some mesh reset to auto-generated convex. Sounds far-fetched in your situation, but who knows. At least, you can test and see.
I hope it helps.
