Battery cannot be verified

Is your signature correct in that you own iPhone X, which was introduced 4 years ago has been discontinued for 3 years, yet you say you've only had it one year? If yes, it was not a new phone a year ago. Apple has introduced new software in the newer iOS which knows if a battery is authentic or not. Evidently your battery is not and the phone you bought was likely refurbished by AT&T or their partner Asurion.

OK.....that's different.

If you know the battery hasn't been replaced in this phone with certainty, schedule an appointment at your Apple Store Genius Bar and they can run diagnostic on the phone.