Why are you keeping the humidity so high? 80% is way too high for BCI. No need for a fogger or as much misting as you are doing. They do fine with 60% humidity. Also, if you are constantly misting the enclosure down the, high humdity will lead to such conditions as scale rot, etc.
Also you should have a gradient of 80-90 degrees (80 on the coold side, 90 on the hot spot). This means one side measures 80 degrees, while the other measures 90 degrees. It is important to know the surface temp, not just the ambient, digital thermometers w/ probes or temp guns are useful for this.
This being said, with high humidity and low temps are a recipe for a respiratory infection. Even if your humidity drops to 50% for a few days or every other day then that is fine, just as long as it isn't during a shed. During a shed you can bring it up to 70% or so. Hope this helped