avast has already changed the text in the confirmation email that you get after submitting a ticket.
It used to say something like “We’ll get back to you within 24 hours”.
It took us about a year suggesting to change the text though
it could be the fact its the same model of phone that its getting confused with
Correct me if I'm wrong. But the old phone was replaced with the new one as I understand it.
Just something you could try.
Login to Google drive and check if the backup really is there.
If it is, deleted the old phone as well as the new one from your account.
Wait e.g. 30 minutes so all changes can take effect.
Connect the new one to your account.
Try to restore again.
I’m not saying this will work, but it is worth to try in my opinion.