I also had trouble keeping humidity up during lockdown. I've got two sponges in one cut up into four piece under the screen and one in two pieces on top, a cloth in the water wells and am keeping a humidifier going in the room. I also have the vents partially closed with tape. Humidity is/ was between 59 and 65 for my hatch. Most of the chicks hatched just fine. I've had several that piped and didn't hatch till the next day. One took 2 days to completely hatch out.. The humidity will rise somewhat once chicks start hatching. Relax they should be fine.