Why are my messages not syncing between iPhone and MacBook?

Yes, I had read nearly every proposed remedy across the web, particularly Apple Discussion Forums. None of them worked for me. In several cases, I encountered iMessage history that included messages and photo attachments on the iOS device which weren't reflected on a Mac Messages client app. Despite numerous attempts at forcing history message syncing. Finally gave up. This needs to be fixed by Apple in a future MacOS/iOS software version.

Correct. Among other suggested solutions. Without success. Ultimately that Mac Messages app would pull down history of iMessages from iCloud, however there would be gaps on Mac Messages (either texts, photo attachments or both) that would. It exist in IMessage on iOS. Those gaps never populated in Mac Messages no matter what. iOS iMessage always provided to be the more complete record.

This is exactly my experience. I concur with your assessment. I’ve tried all the suggestions and the problem persists.

Did you ever get this resolved? I'm having the same exact issue. Thanks for any advice.

I did not