Sprouts

Answer 1

There are many things that can be the cause. The most common is the soil remaining too wet. They will be prone to rotting like that. The idea is to keep them slightly moist with a slightly dry period in between watering. Here is an article that will help you: https://www.gardeningknowhow.com/edible/vegetables/beans/how-to-grow-mung-beans.htm