I e-filed a TY 2021 return for a client in 2022.  In July 2023, I e-filed an amended return for TY 2021.  Further changes were needed and I attempted to e-file a second amended return today when the e-filing window opened again.

I initially received an error message indicating I needed to change the e-file date to the current year.  I did that, and filed it again.  I then got the following error message:   "The submission is a duplicate of one that was previously received.   Please contact customer support."

Has anyone received this error message?  Any ideas on what I should do here?  I tried resaving the file with a new name, but am still getting the same error message.