Is It The Compressor?

As far as your problem is concerned, there are 5 basic, yet solvable reasons for what you described. Please pay particular attention to numbers 1 & 2.

1. The humidity extraction level is set to HIGH. Lower it to 32-35%. If you have a manually controlled unit, set the Manual Control Knob to Maximum.

2. Air intake filter is dirty or clogged. Turn unit OFF, & Unplug the Unit, before removing to inspect & clean it, if necessary. If washed,  allow filter to completely dry before reinstalling. DO NOT operate the unit without the filter.

3. Obstructed air flow. Maintain a minimum of 12 to 18" of clear air space around the entire unit.

4. Cooling coils are dirty and need to be cleaned. Use warm water & dish washing liquid to clean the coils. Rinse and wipe dry. Apply a light coating of WD40 to the coils.

5. Ambient air temperature at floor level is between 40 - 60 degrees.  dehumidifiers do not work well between those temperatures  (Unless, you have a Low Temp Unit). This applies mainly to where the air temperature at floor level is colder than at shoulder level  in basement applications. Raising the unit up off the floor,  onto a sturdy table, counter top, etc, that can handle the weight of the unit, plus a full tank of water, will usually resolve this problem.

If none of the above solves the problem, it may be a case of the compressor needs to be recharged with refrigerant gas or that the humidity condenser sensor has failed. These things usually occur in units that are 5 years old or older. It's rare in a unit younger than that. But, it can happen. If this is the case, these units are so small most manufacturers and even servicers will not repair or cannot repair the units. At that point, contact your manufacturer for their input and possible action to stand behind the product.

I hope this helps!