Q.Dumb Cane care
I can’t get my dumb cane to grow. I was overwatering it last year when it was 1-1/2 ft tall, which caused mushrooms to grow, now it won’t grow.

Certified GKH Gardening Expert
The pot is too large for the plant. When the pot is much larger than the plant, it gets too much water, because of the large surface area. I would get a smaller pot and repot in fresh potting soil. Then get on a regular feeding schedule if you aren't on one. Here is general care of dumb cane:
https://www.gardeningknowhow.com/houseplants/dumb-cane/growing-dumbcane-dieffenbachia.htm