Throw the moisture meter away and lift the pot to check water content. If it's heavy, It's got a lot of water residing. If light, you need to water. Drooping is caused by one of three things, two most likely. Either your soil is too saturated and air is not getting to the roots, or your soil is dry and they are starving for water. The third option is fungus gnats, which eat roots and plant seeds in the soil, which hatch and the larvae start eating roots, hence no uptake of water (again, pot will be heavy, laden with water)
Pictures would help, and I hope my post does as well.