After you file

"line 5b was the amount on line 5a plus the 1/3 of the 2020 disaster distribution from pension minus 2/3 of the 2021 disaster distributions from pensions, that seems correct."

@dmertz 

OK, but this is the first mention of a distribution from 2020 spread out. Are you guessing or did I miss it?

 

In any case, IRS is not accepting the 5b amount.

@dabfvnc1 

I suggest you print your 8915 worksheets and submit them (again?) to the IRS with Form 8915.

The worksheets are a required attachment.