UPDATE: Beeper, through their Twitter account, is saying that they’re working on it and “hope to have good news to share soon”:
Work continues to fix the issue causing the Beeper Mini outage. We know how hard this has been for those who loved using Beeper Mini, and we’re extremely sorry for the inconvenience. We are feeling good, though, and hope to have good news to share soon.
This was exactly it I had to not only deregister from Apple’s services but my friends also had to turn off iMessage send me a message and then they can turn it back on and nothing would be broken. Must be some kind of caching we’ve decided just to switch to Discord much safer that way