a) go into TurboTax. It may tell you why a return got rejected. (For example - mistyping a date of birth; TurboTax will tell you if that was the reason).
b) If you filed late last year, and it hasn't been processed for whatever reason, then the AGI for 2021 (when efiling) should be entered as zero instead of what's on your taxes. That is a subtle reason for a rejection (and it took me a bit to find that answer on TurboTax when I kept getting rejected over and over).
Hope this helps. Good luck!
