I cannot find any info on the given model number, please check it.
Fact is if I Google the number all that comes up is your post.

Check that the condenser coils under the unit are clean. Also that the condenser/compressor fan (if it has one) runs when the compressor runs.
With luck you should be able to do this by just removing the kick plate aand using a flashlight.

It would be a good idea to put a thermometer in the freezer to see what the actual temperature is. It should be between 0 and 5 degrees F. The fresh food temperature is highly dependent on the freezer temperature.

Also check that the evaporator/freezer fan is running. It is required to push the cold air into the fresh food section. They can go intermittent.

If it is a defrost problem the compressor will also run all the time except when it goes into a defrost cycle.
If it does not cycle then when it is warm you will have to remove the rear panel in the freezer so you can inspect the evaporator coils. I am guessing this is where they are but some units have the evaporator coils under the freezer floor.

If they are heavily iced/frosted over then you have an intermittent defrost problem. The reason I say intermittent is that a defrost problem will not just repair itself so one of the components in the defrost system is working only sometimes.
On most units the defrost system has 3 parts.
A defrost heater, a defrost thermostat and a defrost timer or adaptive defrost control board.

It would be rare that the heater would go intermittent. Usually if they had an internal open they will burn out at that point.
More likely would be the defrost thermostat. Check it to see if it is deformed/bulged. If it is then it would be the prime suspect.
Could also be the defrost timer motor is sticking occasionally. If by turning the defrost timer cam, you can force the defrost heater on then I would put it at the top of the list. Be careful that you do not burn your fingers. Usual places for the timer is behind the kick plate, you may not be able to see it as it may be attached to a bracket but usually you will at least see a hole that lets you turn the timer cam. Could also be in the control console, here they also usually have a hole. Or may be at the back of the unit behind the rear cover.

If your unit is cycling when it is warm then odds are that the main temperature control thermostat needs replacing.

Also some units have a thermostat controlled damper which regulates the amount of cold air entering the fresh food section. Perhaps if your unit has this it is the cause.

Without some tech info I am just throwing out ideas but I hope they will be useful to you.