I started my truck up, walked away, came back and I was locked out. I don't have remote entry, but luckily had a backup key. I tested it again and it happened again. Tried another time, and it didn't. Any ideas how to fix? The issues I saw online were of peoples locks repeatedly going on/off while driving, which I don't have. 2003 F150

 

Since you have a 2000, I would begin looking at the GEM for water ingress and corrosion.