Amend 2021 1040-SR & 1040-X Conflict refund #

After efiling 5 days ago and return accepted by IRS.  I need to amend my return as I missed reporting and Interest Income of $605.47.  I ran TT first by adding the Interest Income and also tried start the amendment 1040-X.  Both gave me the same Federal Refund of $4,843 on my 1040-SR. 

My earlier efiling Federal Refund on the1040-SR was $4,988 which is  $145 more.

However,  the 1040-X on Line 21 & 22 indicate that my overpaid and refund was $4,095, which is $748 less than the amount shown on $1040-SR.

But I saw on 1040-X, there is a $748 on Line 18 (Overpayment, as shown on original return) which I believe is wrong that causes my refund go less.  Should that # be $145 or $0?  How can I rectify this discrepancy? 

Thanks