The duty finder doesn't update group info until it has a complete group. I discovered this on my first dungeon after restarting the duty finder a few times trying to figure out what was wrong. I knew there were plenty of dps yet it looked like I was the only one being added to my group. If you are dps, expect as much as a 45+ minute wait although I've had some go quicker. Once a group is found, there will be a pop-up which you have 45 seconds to accept. After that the group x/1 x/1 x/2 will show up. As each party member accepts, the numbers fill in and a check appears on each box when requirements are met. If everyone accepts in time, you will enter dungeon. If a party member does not accept, you should get another pop up quickly (last night it took me 3 rounds of these pop-ups before a full group formed).