El paco, la Bomba,

Hello Kamiel, the soil is too wet! Let the soil dry out for 2-3 days and after you can start watering from the bottom. Put the pot inside a bowl filled with 2 inches water. Let the pot stand in the bowl for 1 minute every day. When you are doing this then you force the roots to search for water. And while searching for water (cannabis plants love it!) they develop a healthier and larger root system. And the roots above the 2 inches got enough access to oxygen.