To the OP, I'd sell the unit and buy something more efficient; something with separate intake and exhaust. This unit just pulls air from inside and blows it outside. There's not even an efficiency rating... because I'm sure it's just awful. You don't want anything that pulls air from indoors and dumps it outdoors.
I've never heard of indoor humidity being too high whilst also needing to heat. It's currently 80% humidity outside, and 40% humidity inside at my house. It's 40 degrees outside, and heated to 69 degrees inside.
You actually want higher humidity to feel warmer. I'd not worry about humidity unless it often goes above 60%.
This is probably the best solution;
https://www.gradientcomfort.com/