After you file

Correction on what you said about the unemployment part because the new adjustment isn't on the 1040X. I amended my taxes and I was on unemployment and my return was exactly the same except for the extra I  got back for the stimulus rebate I amended my taxes for. I haven't received my unemployment rebate yet and I got my return for my amended return 2 weeks ago. I was owed 1,100 and I got 1,108 90 (8.90for interest). Is anyone familiar with the IRS notice CP21B?