oil pressure disappeared.

I am going with the p/up against the bottom of the pan. Don't see how the p/up could crack, it is a looooong piece of tube that can absorb quite a bit of bending before it would actually crack.
My guess is the p/up was very close to touching the pan bottom before the gasket was removed & now it is touching. That design of p/up can cause this, one of the reasons I NEVER use them.