Union collision problem

I am trying to make a trapdoor into an underground room. However the problem is that the hole where the trap door will be is still colliding.

Set collision fidelity in the unions to precise convex decomposition, Performance might drop a tiny bit if you do it to every single one so only do it to the ones you need.

I already tried that and it didn’t work.

I dont know then, Unions have alot of technical problems when it comes to collisions… You might just have to use parts