Did not include sale of primary home

I have completed several amended returns for 1099-B capital loss that my fiance neglected to include in his original tax returns (2017-2019).  During this time I setup access to his IRS on-line account.  Recently a friend of ours received a tax bill from the IRS for capital gains on the sale of their primary home. They did not receive a 1099-S and did not report the sale of their home because their gain was less than the allowed exclusion.  This reminded my fiance that he also sold his house in 2017 and also did not receive a 1099-S.  His capital gains from the home sale were far less than the allowed exclusion so he did not include the sale of the home on his return.   I logged into his account and looked at his Wage and Income Transcript and found that a 1099-S had been reported to the IRS.

 

The amended 2017 return was submitted in Feb of 2021 and we are still waiting to get confirmation that they are processing the return.  The amended return also did not include the sale of the home.  It is too late to file another amended return. I would like to be proactive and head this off.  He has received no notifications concerning the sale of his home but I am sure they will be looking closely at his income when they eventually get around to processing his amended return.