Guild Wars 2

today i did the AC story mode with a few guildies. completed the dungeon, got the dungeon completion chest, but did not get the completion credit towards my dungeon frequenter. also, there was no exit window that usually appear on mini map after you complete a dungeon.

anet pls have a look.

That sounds like the typical thing that would happen when people decide to jump out of the instance too quickly as a result of one of the party members deciding to watch the cutscene. I see that very frequently with explorable and less frequently with story mode but it still happens in both.