Could be that a tax office you have used in the past automatically extended all their clients and you were among them.
I've worked for a CPA firm that transferred ownership. The old owners would update all the past clients they had ever done tax returns for each year, whether the clients came back or not. That's not a big deal, it just means the office was ready to file any of the past clients.
Well, when the new owners bought out the practice they didn't know who was coming back or not and so they extended EVERYONE'S return so no one would have a late-filed return. In the second year, the new owner only updated the clients that were actively using their service.
I have a similar issue this year with new clients of mine. Their old tax preparer didn't know if they were coming back and they filed the extension on April 15, 2021, instead of waiting until May 17, 2021. (2021 is a crazy tax season.) It's May 15 and I am getting that same reject on their returns.
