What is your exact error?
An issue with the 1095-A? If so, there is a cap on repayment, but the 400% threshold applies for 2021. That requirement to repay was suspended only for tax year 2020. If your income is above 400% of the poverty level, then there is no cap on your repayment.
If you received unemployment at all in 2021, then your income is considered to be 133% of poverty line even if it was above the 400% level.