I have no solution and I'm in the same boat. There are a number of threads about this on the forums too, although I haven't seen any DE acknowledgement of it yet. Any chance /u/rebulast can mention this to the appropriate people?
I've seen a couple other threads reporting this get downvoted and filled with replies about NAT and UPNP, so I just want to preemptively say it's not that. Something changed on DE's side over the weekend and people who have been playing fine for ages suddenly can't see friends or clan, but public squads still work fine.
In EE.log, I consistently see errors for the server IP 192.184.13.46. Whenever I do a squad invite, it says it's switching to relayed because that IP is blacklisted and then it times out. I don't think that's the whole story because I often can't even see people online, but maybe it's useful information to someone at DE.