No it is not taxed and you don't have to pay it back. What happened was that on your 2021 tax return you tried to claim it again but already got it so the IRS took it off your return. Check your 1040 line 30 for the Recovery Rebate Credit. Line 30 is only if you didn't get the full amount or qualify for more.
They are not taking it away from you. They just took it off your 1040 return line 30. It shouldn't have been there in the first place. So cross out line 30 and refigure the math without it,
