I’ll send pic, but you can’t miss it . As soon as you look at the brake reservoir it’s clipped on the right side. It’s black about 3/8 with a floating cap on it
There is a vent tube that comes off the front dif, it is attached to your brake reservoir. The smell is coming from there and being sucked into the cab through intake along cowl by your wipers. Sounds bizarre , relocate the tube down along frame . I haven’t smelt it since
Try and do a bms reset. Turn truck on to auxiliary, flash high beams 5 times, pump brakes 3times , battery light on dash should flash 3times . All done