I think this is a new bug. May be mistaken but I have not seen it anywhere yet. So I turned ED-E in to Lorenzo at the Brotherhood of Steel. Then waited 3 days traveled to Primm to find him and full game and xbox locks up. Restarted xbox tried fast travel to Primm - lock up. Restarted walked into Primm - lock up. Waited 2 more days and I received quest message that ED-E was ready at Primm. Fast traveled and everything locked up. Have not tried to walk into Primm from Bittersprings but will try next and I don't see why that would work. I've tried getting into Primm to find ED-E and every time it locks up.

Only thing I can think of is that I tried to go to Primm to find ED-E before the quest said he was ready.

Hope this helps, thanks for trying to fix everything. Huge game lots of bugs but its still fun.

When I got the message, I didn't go to Primm right away and when I did go, Ed-E was trying to walk to where I last was. I had to fast travel to where he now was.
Maybe you can just use the wait function and see if he does the same with you. Just go to a location near Primm and wait a day or two to see if he leaves Primm.