I'm thinking your compressor may very well be toast.
Seen it occasionally,as bee-positive posted!
I usually look up the Kubota part number and do an internet search for affordable replacements.
Good Luck!
I am the stupid dude!
It's been my experience that when the AC system is at rest or empty,the gauges will show approx ambient temperature.
The OP may very will have a bad compressor.
Is the compressor clutch engaged.or is the clutch just turning without turning the compressor shaft itself?
In the Texas heat,those gauge readings look like you're out of refrigerant?
No juice will show about ambient on the gauge.
Good Luck!
Wasn't there a recall/updated hose near the left center of the tractor that would crack and suck air?
And I seem to recall many jerky 3pt complaints that were never resolved.
Good Luck!