Q.dieffenbachia stopped growing
I bought a dieffenbachia in March. It had six leaves on it but now it has only three and it stopped growing. It’s in a nice pot. I water it once a week and it gets plenty of light by the sun in window. What should I do?

The pot looks quite large. You mention watering once a week. Do you check by feeling the soil if it is wet, or just water every week?
I think the plant may be waterlogged. I would recommend repotting into a smaller pot.
A good filtered light near a window would be a great spot for your plant.
After repotting you could fertilize the plant to help it get growing again.
Here is a link with great growing directions.
https://www.gardeningknowhow.com/houseplants/dumb-cane/growing-dumbcane-dieffenbachia.htm