OP could be referring to starting SS, collecting for up to 12 months, then stopping, paying back what was owed, and then restart at a new higher monthly amount.
I don't know much about it except it is limited to once per lifetime, and you can only collect for ~12 months before stopping and restarting. There may be other caveats, but those were the two big ones that I recall.
I've heard about situations where it would be helpful, but I don't recall offhand what those were. Maybe if someone is really sick and may or may not survive a serious illness? But then optimizing SS is probably not high on the priority list.
You can find the page on the SS website that describes the option by searching for it. Edit, here's the page:
https://www.ssa.gov/planners/retire/withdrawal.html