DF queue long for ST on a full premade?

I say full premade but this is just a full group. We just did ST and waited maybe 10 mins max with a group of 5 of us. Then we decided to get a full group from our FC and been waiting forever. It's almost like the DF server keeps rerouting other people to other groups or something strange. Is this normal?

http://i.imgur.com/JnQtQvW.png

I've been having this very same problem solo queuing for ST and most of the bosses actually. I know I queued for ST a few days ago as a PLD and was in queue for over 200 minutes before I finally quit.