Take them out of any sort of "humidity dome" or other sort of unnecessary cover, cannabis does not need extra humidity.
Your plant is most likely suffocated by stale air or excessive heat generated by being under a cover.
Also, clear plastic cups would have to be one of the worst things to grow seedlings in. Firstly, roots need complete darkness to grow and secondly, they are far, far, far too small to allow proper root development at this critical stage of your plants life. Remember, a plants roots will be 2-3 as long as the plant is tall, meaning your seedlings' roots will already be at the bottom and signalling the plant to go easy on growth as we (the roots) are already running out of room. Black plastic pots about 4 inches across and 5 inches deep, filled all the way to the top, are almost ideal for seedlings and their first 2-3 weeks of growth, allowing good root development and rapid plant growth. After spending so much time and effort growing plants, why start them on their journey in life in tiny little thimbles of soil???
I also agree, the substrate in your pictures in your diary, is over wet.
There is no need to water every day, only every 2-5 days and once the top inch or so has dried out.
Hope this helps,...........
Organoman.