iMessage backgrounds not updating across devices or group chats.

When I change backgrounds in iMessage (click on groupchat or contact > backgrounds > select) it will not update across my other devices always. If I change it on my iPhone 14 it will not update on my Mac. If I change it on my Mac it will not update on my iPhone. I’ve had one groupchat where it was successful on both after using my Mac, but just that once.

Additionally, when one of my contacts changed the background, it updated on both of our phones, when I changed it back it only updated on my device. (He also has had the issue where he will change backgrounds and it will not update for the other person/groupchat).

All devices in question are on iOS 26. My iMessage is syncing with iCloud on both devices and I have tried manually syncing iCloud on my Mac.