iMessage not synching on my MacBook Pro (14-inch, 2021)

Hi. I recently purchased a MacBook Pro (14-inch, 2021) to replace my trusty old mid-2012 MacBook Air which was running Catalina.

I've successfully set up my new MacBook Pro, with the exception of iMessage which is not synching to it. I've gone into preferences and it's set up exactly the same way as my MacBook Air which synchs with my iPhone SE without any problems as does my iPad mini 2.

My MacBook Pro synched all my old messages but is not receiving new ones sent to my iPhone SE. I'm able to send messages using the MacBook Pro.

Here's what I've tried:

• Turning iMessages off on my iPhone SE

• Turning off 'enable Messages in iCloud' on my MacBook Pro for five minutes

• Signing out of my Apple ID in iMessage preferences on my MacBook Pro

• Then turning iMessages on on my iPhone SE, logging back into Apple ID in iMessage preferences and turning on 'enable Messages in iCloud

All that did was synch the newer messages I didn't receive to my MacBook Pro. However, new messages are still not appearing on my MacBook Pro.

Any advice/assistance greatly appreciated!