Verification of Non-Filing - But I Filed!

I *thought* I had filed my 2018 tax year taxes in April 2019. I mean, I got a receipt from TurboTax. I have a tax return (that I can still download from TurboTax!).

 

But then when I tried to file this year, it asked that I confirm my Adjusted Gross Income from 2018. So naturally, I look it up on the prior-year return from TurboTax and put that in. My e-file gets rejected!

So, I look it up on the IRS website and while I can download my 2016 and 2017 tax year returns, I can't download my 2018 tax year returns. It says "We received a request dated March 30, 2020 for verification of non-filing of returns for the above tax period or periods. We have no record of a filed Form 1040, 1040A, or 1040EZ using the above Social Security Number. You can consider this letter a verification of non-filing." The "Tax Periord or Periods" is "December, 2018".

So, did I or did I not file my taxes? I'm so confused!