Is that condensation on the top viewing windows I see in your pic? If it is I would say your humidity is much higher than that and what ever you are using to check humidity is off? I have used that type and just added water to bottom water cells until you get it where you want it and it was fine. But if you still need to get it higher you can add wet sponge and it should raise and help hold humidity. I only had to use sponge at lockdown to get it up to around 75%. I also see you have plugs in top of air vents I run mine without those in and still had no problem with humidity but you do have to add water every day or so depending on your climate.
Humidity is regulated by surface area of water not the amount. So you fill as many of the water cells in bottom as needed to get that surface area where you need it for desired humidity. And those cells will be full so as not to dry out to fast and hold humidity steady for longer periods. If you need it higher you just fill more cells. And if you are still not high enough you can add wet paper towel or wet sponge to floor of incubator next to turner in front.
I have the same incubator and I had to play with the water levels a bit along with the two red plugs on the top. I found if I put a little more water than recommended and took out one of the red plugs I was able to regulate the humidity better.
Its actually better to remove both red plugs to let as much fresh air/oxygen in as possible. Especially at lockdown it is much harder for hatchlings to breath with high humidity's. And adjust water for humidity. That has always worked best for me with that incubator, have my best hatch rates that way.
Humidity usually will always fluctuate and not hold 45% all the time you have play with water to get it to hold a range you are looking to incubate in like 35% to 50%. Anything not in that range for short periods shouldn't hurt anything. Very hard to hold constant humidity's in smaller or cheaper incubators.
