We have a few that have worked successfully now too. It seems the key is for both players to restart their devices many times and pray.
It would be nice if Ludia actually communicated how the process was supposed to work as it’s clear unrecoverable errors can occur at multiple points.
With my first recruit, I sent him a friend request to see if it would help link our accounts and I don’t know if that screwed up the process somehow. I understand there’s supposed to be an automated request sent from him to me, which seems to only happen after he restarts his device? Regardless, it’s very confusing and better documentation is sorely needed.