Same issue here on iPhone 12, iPhone 12 Pro Max and iPhone 11. Did my whole family’s iPhone repairs and all had the same update bug. Contacted support and said it was done incorrectly and should go to Apple to get it done “right”. Then transferred to senior from a callback and was told it’s a know issue with 3rd party repairs and said it probably on purpose but should be saying that and the fix is to connect to iTunes to do the update and then all further update will work OTA from then on.