iPhone XR iMessage syncs messages across devices from one sender but not others

[Retsiem]

As the title says: iMessage syncs messages across devices from one sender but not others.

Most of my conversations are stuck 4 weeks ago on my iPad but they are fine on my iPhone.
What could be the reason?

 

[akash.nu]

Sign out of iMessage and back in.

 

[Retsiem]

Sign out of iMessage and back in.

Thanks for the reply. It started working again by itself .....
Really buggy as usual.

 

[southerndoc]

Yes, it periodically stops working for me. Sometimes just quitting the app on macOS will fix it. Other times it doesn't. My issue is always messages not appearing on my MacBook Pro and/or iMac. Most of the problems are from SMS texts, but occasionally involves iMessages as well.