If I had 1099-INT forms for both my banks for 2020, is it possible that I don't have them for 2021?

If the interest earned is less than $10 then the bank is not required to provide a 1099-INT.  The interest paid should be available on the website for your bank account.

One will not be produced if your interest earned was less than $10 however the interest earned still needs to be reported on the return ... simply enter the name of the bank and the amount earned which should be on the January 2022 statement for the 2021 tax year.