Messages doesn't send messages anymore

[SR 7]

So I wasn't able to send text messages via my MacBook Pro to some people when I first updated to Big Sur. I would get the "Message not delivered" error. I contacted Apple and htey tried to fix it but couldn't. After I told them several people have this issue they admit that this is an issue they are working on.

Now I have more people I can't send messages to using the app. has anyone been able to fix this damn issue?

 

[0128672]

You want to know if users have fixed an issue that Apple acknowledges and hasn't yet been able to resolve? What were all of the detailed steps done with Apple Support?

 

[appltech]

I'm curious what the Apple tech's did? Did you manage to oversee what they've been doing?
What I'd try first is simply logging out of Apple ID and logging back in (in Apple logo -> System Preferences -> Apple ID -> Overview -> Sign Out and then sign in again).
In extreme cases, reinstall via Recovery might help with Apple's built-in apps link (backing up critical data is advised).