I have just got a new (2020) iPhone SE, and having an issue with iMessages.
I was previously in a group conversation - most of the recipients are phone numbers (with iPhones), but one is an iCloud email address. Since I got the new phone, I can't see any messages from the person using their iCloud address. And they don't see my messages. Everyone else in group chat can see our messages fine.
What's going on here? I've tried turning imessages on and off. Any other tips?