Serial & Restore Codes Failing

I got a new phone a few months back. I have been unable since getting the new Battle Net App to set up my authenticator on my new phone. I’ve cleared the cache, deleted data, uninstalled/reinstalled. I’ve uninstalled the old app. I’ve detached the authenticator from my account. No matter what I try, I cannot get the new authenticator set up on my account.

Even time I try to set up the codes, I get the “Hmm…something went wrong. We are having difficulty retrieving content from our servers. Please try again.”

This has been happening for months. Any advice?