To those who may find this thread
I resolved the problem. I neglected to include the amount of our second COVID relief check. When I updated my 2020 tax forms with that amount, it nullified the "Recovery Rebate Credit" (form 1040 line 30) which just happened to be the $147 difference.
I do not have to wait for a letter from the IRS explaining why our 2020 refund was not the amount I expected because I signed into my IRS account and the reason was spelled out clearly.
