Apple's System-wide Messages / iMessage / Messaging not syncing between devices (laptop/computer, iPhone, and iPad)
June 26, 2022 - There is no fix as of 1:40 Pm Pacific time.
There is an Apple-wide issue with Messages not syncing whether in regular or Safe Mode, the original User ID or a Test user ID. It does not matter whether blue or green response bubbles; both are not syncing completely.
Some messages sync and do not sync between iPhone, iPad, and iPhone.
SUGGESTION: It would be nice for Apple to create an "Apple-wide Issue" page with a searchable topic field of known issues with hardware and software. It would be good to also have each issue updated hourly (with a message "Still working on it" or "Fix the issue: Here's how" messages. This would save Apple customers and advisors from having hours of phone conversations to only get the message at the very end that it is an "Apple-wide Issue". It would also help lower the costs to Apple and the customers.
MacBook Pro 15″, macOS 12.4