I have 4 large, I guess you'd call em sweaterdors, @ 70 liter plastic containers like you buy at Walmart. 3 of them are Sterlite brand & the humidity runs pretty good in these. I have 1 Rubbermaid that I keep loose cigars in baskets. I have maybe 400 cigars in there & my rh is running too high (@ 80%). Maybe this box seals better than the others. I have taken out some of my humidification devices & added some cedar blocks & sleeves to it, but it hasn't helped much. Am thinking about drilling a hole in the side to allow some breathing ability. It has also occured to me that since I have a lot of cigars out of their boxes packed in here, that maybe the air is more displaced in this humidor than the others Where I have thw cigars still in boxes.
Any thoughts?

Could be the cigars are wet now too. It's going to take awile for the humidity to come down. Take out ALL of the humidifiers and see what happens. When RH starts to drop, put them back in one by one until it stabilizes. Don't drill any holes just yet.

I had the same problem with a rubbermaidador. . . . I used a small block of floral foam, with Prop Glycol/water 50/50, and I lined it with cedar. . . . It was always 76-78%. . . . I took the humidifer out, and a month later, it's still at 68%. I think it's the cedar, as I had wiped it down with a damp rag at first. . . . . I think the cedar absorbs the moisture, and it's acting as a humidifier until it dries out. . . . and if the box is sealed, it won't quickly dry out.