Prior Year Refund Less Than Return - Which Amount to Enter in 2021 Return

[Edge10]

For 2020 the refund amount received was less than shown on my mother's return.  There was no offset letter from the IRS and the online refund status still shows the return is still processing.  I have reviews the errors and reasons for the offset , but not found any issue.  The only item I can see  is the IRS did not add the amount sent with the 2020 extension, since this is the same amount of my offset.

What refund amount should be entered in the 2021 return : the reduced amount from the IRS or the amount shown on the 2020 return?  How best to receive the money owned or explanation for the offset ? I would prefer to  write or email the IRS to resolve this and spare my mother the stress of the call.

[DoninGA]

Prior year federal tax refunds, received or not, are not entered on the current tax year federal tax return.