Filed 2021 return with the rebate credit for my missing 3rd stimulus payment. Did not recieve the 1400 with my refund and recieved a CP12 notice from irs.

I did not recieve my 3rd stimulus payment. Applied for the rebate credit for that payment. When i recieved my refund the 1400 was not included. I then recieved a CP12 notice from the irs saying my refund was changed about 300$ but it does not say anything about the stimulus. Do i need to amend my 2021 return to recieve the payment?