Okay, Volbeater and I have been fighting with this issue since the week of release. We had friended each other and were able to join each other’s servers and team up perfect since launch day. Then about a week later, there came a day where it showed both of us Offline when we were on. We tried all kinds of things to fix it, including removing each other from our friend’s list. Since then we haven’t been able to re-add each other as friends and thus we couldn’t group.
Apparently, Bethesda assumed if you Deleted a Friend, you must want to Block them too. ;( Yes Virginia, there IS a block list in FO76 you just can’t see it in the PC version yet. (both consoles can edit it)
So here’s what we did last night to get around it.
Find a nice, helpful OTGer to assist (Thanks again Daveon!) Get them to friend you and your other friend that you can’t put on your friend list. Once that is setup, get the 3rd party to invite both of you into a group. The group entrance routine will notice if someone is blocked and ASK if you want to remove that block. Once that’s done, you’re good to go again and everything works normally!