Still, the Health Insurance may be the reason.
Certainly, it may have been pre-tax before they closed and while you were getting paid, but after they closed and you had no income, they may have had to switch to an after-tax basis, since they were paying all of it while you had no income from them at all.
The $2 difference in Fed taxes withheld is inconsequential and could just be rounding.
The Medicare and SS difference is likely all due to the extra $4000. (more like the ~3700-3800 range? )
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
