Heat Pumps and Electric Heating - Heat Pump gets wet - freezing over

Recently, we discovered that the Cooling unit in the apartment upstairs from us was leaking water into our Heat Pump closet. Since the closet was closed and we didn't hear water running, it remained damp in the closet for probably 2 weeks. Once discovered, we let our upstairs neighbor know and we left the closet open to let it dry out. The inside of the unit seemed to stay pretty dry and continued working (but I don't know what the condition of the ducts above our unit are now that they've been soaked with water and dried out)

Its been dry for about a week and a half now - yesterday I noticed that our thermostat just kept going up and up, even though it was set to 79, it got up to 83 and the unit remained on (outside unit was running, and there was no sign of ice in the outside unit at all). I noticed there wasn't much air coming from the vents. I opened up the interior unit and saw that the fins were frozen solid. I let it thaw and turned the unit back on. It remained on for 2 hours but still did not fall below 81 degrees, despite the fact that cool air was coming from the vents. Checked the filter, and it is nowhere near being ready to change.

Is this because of some regular maintenance problem (freon, etc) or is this a result of the dampness it recently experienced?

P.S. Is there any way to make it smell less moldy now that its dry?

Filter clean ????coil clean???? blower ok??Next could be low on freon. Id say call a tech to check the freon in it. also might check for any leaks in the freon

Filter clean ????coil clean???? blower ok??Next could be low on freon. Id say call a tech to check the freon in it. also might check for any leaks in the freon

Filter was changed about 4 weeks ago - barely dirty.
Coil was covered in ice and got a nice wash when it all defrosted I'm assuming.
Tech is coming to check on freon I think.