GAP Insurance Payout?

I'm wondering what will happen if anything. My car was totaled and my lender took forever to get my GAP claim filed. The GAP claim has finally been finished up with and the check was sent out to my lender.

I missed this last payment due to having another car payment now. Looking at my payoff quote and looking at the amount GAP paid, it looks like once it is applied to the principal amount, it should cover the whole balance. I'm wondering if the lender can still come after me even if the loan is paid off. My thinking is they're getting their money, but they could charge me a late fee I guess and report the missed payment on my credit.