Sounds like they are operating fine with temps in the 40s coming out the vents, in our class a gasser we have RVed in 100+ temps without issue, we just crank them down to the sixties and let them run until ACs have removed most of the heat trapped within the rig.
With temps in the mid 80s the front curtains and motorized blinds are enough, when temps are 95 and above we will implement our windshield sun shade that we have cut to a perfect fit, it covers entire windshield and front side windows deflecting much of the incoming heat.
Unlike homes, even the best insulated RVs will contain heat that is not as easily dissipated, cranking down AC units and keeping them active throughout the entire day and night is the only way to truly stay ahead, waiting for temps to peak before activating ACs is too late.