Lockdown, humidity won't rise

[Altairsky]

Hello, I've started lockdown today. I always kept humidity at 30% by filling 1 tray out of 4 with water. This morning I filled 2/4 and got the humidity up at 45%. After a few hours, after humidity stabilized, I filled 3/4 hoping to get 55% humidity... But instead it dropped back to 30% and never went up. I don't know how this could be even possible according to the universe's law of physics. Now I'm afraid if I fill the last tray I might bump up the humidity too much.
What should I do? I have 2 hygrometers inside the incubator and they both agree. It's also my first hatch so I'm really confused and afraid to mess up!

 

[Altairsky]

One egg is pipped. Incubator full of water, humidity still 30%.
I have 3 options:
1 - do nothing and let the chicks hatch at low humidity.
2 - spray warm water around the incubator sides and top.
3 - the bottom of the incubator is cold so water does not evaporate: add a heating pad under the incubator to trigger evaporation.
What do you think is the best option?

 

[My15Ducks]

You could try filling the last tray, or add an additional tray of water (Ex. A cup or something)

 

[Altairsky]

I had to put almost half gallon of water and a sponge to get the humidity at 60%. One hatched early (day 19) the others are all externally pipped.