All the motorhome AC units I know of, there is a fan setting on the thermostat. If you set the fan to 'AUTO' the fan should cycle with the compressor. If the fan is set to either hi or lo, it will run continuously.
Ditto on what Laco just mentioned. You need to push the Mode button until you see the green light next to FAN is lit. Then push either the "+" or the "-" button until you see Auto in the display and leave it there. Then push the Mode button until your green light shows up next to the A/C (or something like that) position. Adjust your temperature and wait a while to see if that solves the issue.
If it still gives you problems repost again andmaybe someone else can chime in with suggestions.
Ed & Robin Lively
with Nina, Kitt, and Mickey
2016 Thor Synergy TT24 (a.k.a "Ming")
Here is the scoop on the unit you have which is similar to the one in my previous 2015 Four Winds 22e. Facing the control knobs, the right one controls a relative temperature, it is not precise like a thermostat. It serves to only cycle the compressor. The left one is either off, low fan, high fan, or cool. On the cool settings, the fan runs continuously. It is a simple AC, works like a window unit.