Do you have a thermometer? If so, what temperature does the AC put out at the vent nearest the unit. It should be 30 or more degrees colder than the outside air. If it isn’t, first step is to be sure all the fins and filters are clean. Be sure it isn’t icing up due to running continuously. If that doesn’t help, time for professional or maybe replacement.
If the unit is cooling at the vents, time to start insulating the rig and defeating solar gain. Park in the shade if possible. Keep blinds shut. Pull all curtains shut. Avoid putting heat and moisture in the rig . Things l like cooking, doing laundry and showering and opening and closing by the door multiple times all go towards defeating air conditioning.
The hard truth is most RVs are not well suited for temperature extremes. The chassis build is not sufficiently insulated, the windows are not thermally efficient, and by default even the undercarriage is exposed to the elements unlike a standard residence that is attached to the ground. Florida in the summer is just as taxing on RV climate systems as North Dakota is in the winter. It can be a losing battle.
