I'm also experiencing this issue. It's been happening for a couple months now. The first time it happened I was trying to join a server on the experimental dayz app on xbox to attempt to play. I then tried joining on the actual game app and it did the same thing. The first server I attempted to join was Dayzchain and now none of them work. I've been able to join once since then and didn't stay on long enough to see if it froze.