If sufficient $$ were in boxes 3 & 4 on multiple W-2 forms...a W-2 assigned to the wrong person can result in an improper SS refund that goes away when the W-2 is properly assigned.

Thought of, & threw out several other ideas.......maybe someone else has some other detail that would give a  similar result.

IF you were set up to get more stimulus on that tax return, maybe moving things around changed it, and you have to run thru all of the interview sections to reset the first or second stimulus amounts.

Maybe something to due with healthcare insurance?  Run thru those questions again too.