This isn't a problem, it's more of a community service comment.
So I got a new phone for Christmas (yay!) and used Google's system for transferring settings and apps from one Pixel to another.
Since Bitdefender was on the old phone, it auto-installed Bitdefender on the new phone. That was actually kind of impressive.
The gotcha is that the Pixel transfer system has no way of knowing what your Bitdefender account is or the access code. If it did, that would be an enormous flaw. Everything to this point is correct, but your new phone doesn't have a subscribed Bitdefender account.
So Bitdefender when it starts on the new phone auto-creates a trial subscription. This is different to if you buy a new phone and then install and activate Bitdefender from Central within your subscription.
Logging in to your Bitdefender account on the new phone DOES NOT get rid of the trial subscription. You have to manually remove your old phone from the devices list in your subscription, and add the new.
In my case at least this left me with two device records for the same phone: the one created with the trial subscription and another created when the same phone was added to my subscription. You then need to remove the device record auto-created for the trial. Now you're done.