As Rustic Eagle noted the tongue weight is carried by the tow vehicle and not the trailer axle. When unhitched it is carried by the tongue jack. Our previous 195RB Baja was similar with a 3750 GVWR but a single 3500 axle. I think this is fairly common on the smaller campers though I've seen some tandem axle units where the axle ratings don't cover 100%+ of the GVWR.
We usually ran very close to the GVWR with ~450 tongue weight and 3250 on the axle. That was with a second Group 24 battery on the tongue plus the larger 30lb propane tank. I would recommend running it over a CAT scale all loaded up to go camping to verify just how much your axle is carrying. Given that with the smaller campers they tend to run much closer to the GVWR when loaded I always wanted to know just how close I was on the axle.
TT: 2019 ORV Timber Ridge 23DBS, Blue Ox SwayPro 15K/1500
TV: 2019 Ford F-250 XLT SuperCab LB, 6.2L, 4.30/e-locker, 4x4, 164" WB, 3216 payload
TV: 2014 RAM 1500 Big Horn CC (Traded in)
TT: 2015 Jay Flight SLX 195RB Baja Edition, Andersen No-Sway (Traded in)