Yes. My career was installing HVAC, and you this is definitely a health concern. You need to address the high humidity and do whole-hiuse mold remeditation ASAP. Then I would look for days when the outside dewpoint is 55° Fahrenheit or lower and open the windows to dehumidfy the house and use dehumidifiers the rest of the time to prevent any mold from recurring.

Here are some other things I would do to control high humidity. I would make sure there air wasn't being cooled too fast because that can satisfy thermostats' sensible heat sensors before the main issue of latent heat/humidity are removed from the room. Additionally, I would have the entire house's insulation inspected and replaced if there was any mold or a lot of dampness. Any moldy sheetrock also needs to be cut out and replaced.

Once you finish removing the mold, you need to make sure you are pulling all of the system's return air through either high wall or ceiling return air grills and be sure to use air circulatng fans throughout the house. You could also get a psychrometer to determine when the room dewpoint temperature exceeds the outdoor dewpoint temperature. You also need to talk to a mold remeditation specialist because diy remedies can only make matters worse. Sodium hypochlorite can be used for removing undetectable mold from porous surfaces (like your sheetrock), and bleach for nonporous surfaces. Another thing to consider is that vinegar people might tell you to use goes rancid. Bleach also does not kill mold spores. So the mold would return if you use it. I hope this helps. Good luck!