How are you measuring humidity? Many humidity gauges can be off. I use for a range not exact like an IR temp gun.
80% humidity for a short period should not cause in RI, if it is that high. Especially if temps are correct and you're not dropping them at night. I do not recommend that and further low temps and high humidity is more likely to cause an RI than slightly elevated humidity and correct temps to help shed.
Take a deep breathe. It is very easy to neglect a reptile, but just as easy to overthink, tinker, and cause problems.
It sounds like you have temps dialed in, are aware of humidity, want to keep the cage clean, want to feed appropriately, etc. That's what matters.
I used to keep fish and there is little margin for error especially with certain species and water quality. Reptiles are a little more forgiving in most instances.
Get things dialed in and then let it be. Check temps daily, keep the cage and water clean, feed, etc. You will be fine. If every waking minute you are worried about your pet, you will burn out. Trust me, I have 11 tanks and 11 reptiles. If I was that meticulous about every tank and I would have zero time to live and/or enjoy the reptiles.
I am not trying to give you a hard time, but rather encourage you. You seem to be on top of things. Have a little faith in you. Relax. Enjoy your new BP.
Any questions feel free to ask. We are here to help.