any idea why this is happening?

hey there guys so i am using the coconut husk bedding that u can buy the bricks of and soak in water and bam u get the big tub of substrate. so thats what i am using for substrate for my ball pythons. i have checked and double checked that the humidity levels are where they should be and the substrate is not soaked or moldy or anything but the walls of the tubs are very condensationy but yet parts of the substrate are dry. i go in an check the bins daily and mix the substrate around so its all even for the levels of dampness i guess u would call it, so why are the walls getting like that? its not harming the snakes they arent sick or anything but i just found it odd as when i had my one guy in a terrarium this didnt happen but now that they are in the rack bins its doing this. any advice

Have you put any holes in the tubs? Tubs have very little airflow to keep moisture from building up. Generally speaking if the tub is condensating you need more holes.

What is the actual humidity in the tub?

the actuall humidity in the tub right now is 70 and there are air holes they came pre drilled. i i could try putting more but it does have alot already.

Do you have any fans going in the room? 70 is a little high to have on 24/7 in the tub, that much humidity is only really needed when shedding. Mid 50's is fine for the rest of the time. Are there big water bowls in there?