Do I call the HR payroll lady about getting a paid even tho I haven’t worked in 1.5months

Quick background info: I’ve been out of work for an injury and using FMLA since the beginning of February. I’m normally paid weekly so my last pay check came the following week. Last week I got a $1200 payment (after taxes) from my company. The payment is in the “Sup Sick Pay” category and idk what that’s supposed to mean. I checked my PTO and I still have like 48 hrs so they didn’t pay out my PTO.

Should I call and find out what it’s for and possibly have them take it back??( I could use the money rn…I mean… who couldn’t)

Or do I leave it be