Does your custom mesh itself have collisions ? That solved a similar issue for me.
I wanted to use a LightBeam mesh from the engine itself as overlap collision and it wasnt working even tho it was set to “OverlapAllDynamic”.
I copy pasted the mesh itself, opened the copy and changed “Collision Complexity” to “Complex Collision as Simple”.
You could also just add a box collision or whatever other collision if you don’t want to change “Collision Complexity”.
Opening your mesh itself and changing view mode (top left) from “Lit” to “Player Collision” will allow you to see if thats the issue.