Barrel nut wont thread on - TRYBE Defense AR-15 Stripped Upper Receiver Type II Mil-Spec

I wanted to use the trybe ultra light handgaurd. So when shopping for a upper for the build I thought surely I wouldn't have fitment issues using the same brand upper...But no. Mind you, I am a marine technician for a living and turn nuts and bolts daily for a living. Forget the fact that I've been building rifles for years. Nut wouldn't thread with or without barrel installed .Threads on the barrel nut look fine but the threads on the upper were boogered. Likely from the poor packaging as it came in a plastic bag with no padding.