Legacy Dungeon "Sticky-ness" when leveling

So I've run into an issue where if I'm doing Legacy LFG. I'm leveling a new team and I'm doing Cata/MOP for instance. I'll be doing random dungeons, and eventually I'll run into one where the instance is overtuned or just more difficult than I'm really willing to work through at the time. Anyways, when this happens, if you leave the instance and start a new LFG, it will take you back to the same dungeon over and over again.

I don't know if it's sticky because of being in the same group or what. However, I have found that if you completely exit the game and come back in you'll get a different dungeon. Not sure how useful this is but figured I'd share.