LetPot system not making my plants happy

Hello,

I purchased a letpot system a month go and have been attempting to grow cooking herbs in it since. Most of my plants have germinated and started growing since, but they're all drooping and looking sad. I followed the directions on initial set up and im not sure why im not having success with them. I've been keeping the system in a ventilated green house cabinet that hovers around 71⁰ F and 45-50% humidity. Any help would be appreciated. I just want to be able to grow some herbs and veggies for my home.