2555 HST Cab won’t start…

2016 2555HST Cab.

I plowed snow for about 2 hours this morning with no issues. When I was finished, I locked the brakes and after I turned her off, I topped the fuel up (from 3/4 to all the way full).

I came back to her about 5 hours later and now she won’t even turn over!

I have 12.9 volts at the battery, and about the same at the starter. I put a JumpPack on the battery and still won’t turn over.

All the lights, radio, and heater blower work just fine.

I pulled every fuse I could find and they were all good.

It has been about 16 degrees here but she started this morning.

Any suggestions or troubleshooting is appreciated!!!