Maybe check the duct work for obstructions/good air flow.
Run the fan on high in high humidity environments.
Check your AC unit to see if it is affected by the TSB regarding drain pan leak
https://www.montanaowners.com/forums...hp?do=cat&id=3
For drying out your ceiling, I would put a vacuum on the rear attic mushroom cap vent to draw air through the attic to dry it out as fast as possible.
OR cut the top and bottom out of a box, place it over the vent then lay a fan over the top to draw air through to dry the attic out. This would probably work better since you will need to let it run for days.