OK, so I finally manages to play Forge Island on Forge after deleting the map I had downloaded before getting Forge Island. I spawned with a Needler and half of a Incineration Cannon. The front end of the cannon looked fine but the rear half simply wasn't there, including the hand hand grips. Would have loved to have taken a screenshot but when I tried loading the clip I got the same glitch happen where I was sent back to the main menu. After that I couldn't go back into Forge Island without getting sent back to the menu. Works fine in custom games oddly enough. Will try to delete and redownload again.