I had something similar happen with my CA state taxes once. I filed my taxes and ended up owing, paid what I owed, and then a few months later got an unexpected refund of $50 and change. Once I got access to my online account (Which in CA requires signing up, and then waiting to receive your initial password in the mail – the Franchise Tax Board’s website is incredibly clunky) I figured out what had happened. In CA you can contribute various charitable funds on your tax form, which I did. Except for some reason my contribution to that fund didn’t get processed, and they treated the amount I contributed as an “overpayment” and refunded it to me. And they paid me interest on my overpayment, which is why the refund was $50 and a few cents rather than an even $50.
Did the OP buy a used electric vehicle from a licensed dealer in 2023? The federal tax credit (as part of the Inflation Reduction Act) for that tops out at exactly $4000. The paperwork would likely have been submitted by the dealer.
No.
Or, at least I hope not 