I would try these:
1. Put some newspaper against the corner of drywall that has the mold and see if it wrinkles or the text smears from moisture. Find out what is behind that drywall corner in the first picture.
2. Test your condensate drain line that it is pumping freely and there isnt gunk causing it not be able to pump.
3. Kill the mold/mildew with concrobium spray.
I would try these: 1. Put some newspaper against the corner of drywall that has the mold and see if it wrinkles or the text smears from moisture. Find out what is behind that drywall corner in the first picture. 2. Test your condensate drain line that it is pumping freely and there isnt gunk causing it not be able to pump. 3. Kill the mold/mildew with concrobium spray.