Hey guys, that was none of the issues. There was collision on everything, the camera was socketed, etc.
I figured out the problem. It wasn’t my fault, but rather how poorly Unreal Engine handles physics on small objects.
My marble was about a couple cm in diameter. When you have a player on such a small scale, you cannot prevent clipping.
Doesn’t matter if you change the clipping plane to 100000, 0, or -10000. It will make no difference to unreal. It can’t handle the camera at such small scales.
Once I scaled my marble up 10x, the clipping all went away. Unfortuantly I had to scale the world up 10x as well which caused a huge issue with lighting, as everything is always too dark now.
It sucks but until there’s a special functionality in Unreal that lets you deal with games on a much smaller scale, this is the workaround.