I am in the same situation, I even retried this morning to send a new link to my son. He clicks the link and asks him to start a link with me, box pops up with a “link successfully” message and then that’s it. It doesn’t even actually shows a link like I have seen others have. Ironically enough, in game we can see the “guardian unite” buff on his character. I hope this gets resolved before the period of time runs out.