Your hood fan and light will be 12 volts. If all the fuses test good (not just looks) then you may have a loose wire somewhere. I'd start at the hood and work your way back.
Since this is a 2018 model, If it's still under warranty, I'd contact the dealer and see how long it'll take them to look at it. If you don't want to wait on them and you're pretty handy, you can check several things yourself.
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!