STP2 out of balance

I ran reports a month ago to check STP2 balances against payroll history.

I had a few out of  balance.  These were termination payments that hadn't been submitted.

A couple of days ago, I revisited the STP2 balances and I now have 2 employees whos wages have not got through to STP since November 2022 (Note, their balnces were correct on the previous check)

Anyone know why this has happened and how I fix it?

TIA