After I completed ED-E My Love, ED-E no longer helps in battle. She stays behind after a battle until I enter a load screen. She then shows up. I decided to go back to the Presidential suite to switch ED-E for Rex and Rex is gone. I'm 100% positive I left him there. I checked back at the The Kings School and he's not there. I now no longer have a secondary follower. This happen to anyone else???

Yep. except I cant complete the ED-E quest so I dont have that problem, but I left Rex at the lucky 38 and he is gone and now i cant complete his quest.