They are growing on the sides and bottom because those parts are recieving light...
Suggestion:
Cover up the sides and bottom of container by:
*using foil
*using dark colored tape
**Or my personal way, taking another container, exactly like that one, and painting or covering it to stop light from getting through, all sides and bottom. Then place your clear one directly inside the dark one when putting it in fruiting chamber.
It works great because; 1) you still have your clear container with colonizing sub in it, that will be visible all throughout so you can watch progress while colonizing. 2) You can just place the clear container in the dark one, 1 easy step! Keeps the light out, and no wasting foil or tape everytime. Or whatever one chooses.