AC systems can only pull the temp down about 20* at a time, depending on how yours in insulated or the size AC unit you have it might not be able to keep up or it might take a long time to cool the interior down fully.
My old TT with poor insulation and a single 13.5K AC would never keep up even if it was on from the beginning of the day, 80-85* during the day when it was 95* or so with direct sun.
Now, depending on your outlet temps you may need to see about it getting serviced. The outlets should be able to spit out 40-45* if measured directly at the closest vent, after running for 20 minutes.
Now-2014 Sierra 346RETS 5er BUB
Then-2002 Keystone Springdale 286RLDS TT
Nights camped in 2014-28, 2015-127, 2016-10