Trans leaking from bell housing

Just fire up a fresh new build and was about to take it on its first drive when I noticed the trans started dripping as I pulled away. Got under it and it seemed it was leaking from the pump seal. Removed the trans and replaced it only for it to leak again. What I did notice was the seal had some wear on it, what could it be? It’s a freshly rebuilt trans and a brand new torque converter.