Hi
So 50% isn't so bad, but I can definitely understand wanting it to drop a bit more. I would grab an intake and an exhaust fan for the space, anytime I run my outgoing fan with my in going my humidity and temp always drops. It might also be good to try to not do the watering in the evening towards lights out because that will cause a spike in both temperature drop and humidity rising which is what usually will cause the bud rot , mold type situations.
Happy flowering.✌️