Cut In = the "on" temperature. ( how warm it gets before the compressor turns on.)
Cut Out = the "off" temperature ( how cold it gets before the compressor turns off.)
If your thermostat is an air temperature sensing type & accidently is in contact with the evaporators metal housing
Or is touching a cold line, it could cause the unit to "short-cycle" as you've described. perature ( how cold it gets before the compressor turns off.)
I knew I mixed that around. Terminology aside should of got the idea. Yes, did you use a thermometer which would be the first step...