i killed the creatures in dungeon to get to the boss but when i got defeated and went back to kill the boss the creatures came back, what's going on, before in a dungeon once the creatures were killed they didn't come back
dude, are you sure is a dungeon? Towers in DragonSpyre are not dungeons. They don't allow portings. They will clear your progress if you leave. But everyone who have that quest can enter with you. And some dungeons like The Labirint are like wierd. They will clear progress if you leave. Wierd......
I had this happen in MB the other day: Was doing one of the side towers before Meowiarty. Was defeated after defeating one of the minions, went back and that minion was gone. Was defeated again after beating second minion, went back in and both minions were back! Not sure what happened. But I have never before been defeated twice (this was with my myth wizard which I find more difficult than others) so am not sure but suspect that maybe you get one free shot then have to start over. Really not sure.
This happens sometimes. For various reasons, the server thinks that you left and re-joined the dungeon, so the enemies are back. It doesn't happen often, so it isn't something to worry about.