did you read the instructions for form 2553 regarding late elections
https://www.irs.gov/pub/irs-pdf/i2553.pdf
by te way as an LLC the CPA should also have filed form 8832
there are specific steps that must be taken
failure and the IRS could treat the 2020 S-corp filing as invalid and tax all that income to you as if you filed a schedule C and improper filing for 2021 could also be deemed invalid
I strongly suggest you seek the services of a pro to review your situation