My message app is not receiving messages on my new iPad Pro. I am still receiving them on my old iPad Pro.

Are you having difficulties with all received messages reaching your new iPad - or just SMS/MMS messages that are relayed from an associated iPhone? Something else?

Assuming that all devices are signed-in to iCloud with the same AppleID - and that you have an iPhone - to send SMS/MMS messages (green bubbles) from your iPad you must explicitly enable Text Message Forwarding for your old and new iPad on your iPhone...

On your iPhone:

Settings > Messages > Text Message Forwarding - set to ON - and explicitly enable your iPad from the list of devices.

Also ensure that Messages in iCloud is enabled on both your iPad’s and your iPhone:

Settings > [Your Name / AppleID] > Messages - set to ON

That setting also shows specific devices so that might be why one iPad Pro gets the messages and the other one does not.

Hope this helps.

Paul

You are very welcome. I’m delighted that the problem was easily identified and resolved.