I think this is new to irs system.  That would cause a lot of problems to tax preparer to transmiss the returns 

My new client used to file 1120S 2020-2023 TYs . I don’t know if she ever filed or had 2553 S Corp election before 

2024 I efiled extension and rejected. Calling irs e help desk is waste. Írs officer advised to call business and specialty line department and not authority to talk 

Another client has been approved to tax classification as SMLLC approval 4.30.24 ( changed from S  Corp with 8832 election )  We need to file final S Corp return but rejection too. I had to mail final return S Corp 1120S 

Another client filed S Corp with attachment 2553 since 2021 -2023 going through efiled  Lately 2024 we received irs notice the business entity is S corp effective 2022 approval 

What is the ! 
i found this forum and know the issue recently 

Thank all experts