Did you plant them in some kind of fish tank without drainage? Looks like that from the phote..... even though they need high humidity, doesn't mean that they don't need good drainage. I usually plant them in 2.5 inch pots and place all of them in the tank and seal. Sometimes I will also put a thick piece of tissue to act as matting. The temperature is getting higher... don't cook them.
Whenever I get a new one, I'll remove it from it's pot and seperate them into different pots if there are suckers. It's a good way to give them clean new soil, check for diseases and have suckers for friends.
