Normally the words get added in the order of the list and the green spot next to the list means that I already studied the word, right? Or does it mean, it got added to the queue, no matter if I actually studied it or not?

Today I made a new list and specifically added a lot of words with the character 僵. When I practiced this list, I kind of waited for those words to pop up, but the programme just jumped over it and let me practice all characters before and after those words... I just checked "my words" and those words are not in this list. But nevertheless, they got marked with a green spot in the vocabulary list. Shall I continue to only study this section or add the words to the queue list to make sure, that they will finally pop up?

Ok, problem solved.

Because the words all had 僵 in them, they couldn't be studied at the same time, so they were spaced out a bit. They were added, though, so they'll get their turn eventually (as I guess you've already seen).