Ohio State Tax Offset Notice for 2016 When IRS Has No Record of My Return - Possible Identity Theft?

Just checked my transcript and got hit with an offset notice from Ohio for 2016 taxes. They're taking my state refund but I've never collected unemployment or had any state tax issues that I know of. Super confused about where this is coming from after all these years. I decided to contact the IRS to see if they had any information, and I received a letter dated January 27 from the Internal Revenue Service (United States Department of the Treasury) from PHILADELPHIA, PA 19255-1498. The letter has a Tracking ID: 1073284 and refers to my Tax Period: December with Return type: 1040. The letter states: "On January 27, 2025, we received a request for verification of non-filing a tax return. As of the date of this letter, we have no record of a processed tax return for the tax period listed above." The letter also mentions "If you have any questions, you can call 800-829-1040." I'm completely baffled because I'm pretty sure I filed all my returns properly. Why would Ohio be claiming I owe state taxes from 2016 when the IRS has no record of a processed tax return? Could this be a mistake or identity theft issue? Has anyone dealt with state tax offsets when the IRS shows no record of a filed return for that year? I'm worried this might affect other refunds too.