I have just completed the elden roots dungeon and was to told to speak with lights for reward but she was invisible on my screen so couldn't collect everyone had received reward
Relog in place and see if they come back. One thing nice about Group Dungeons is the Mob Spawns stay dormant until you leave and come back after you kill them. Its so you can ressurect at the entrance and not have to fight your way back to the group. They might even stay dormant until you collect, but not sure on that. So, don't leave the dungeon until you have tried the relog.
In your Journal did you get credit for the Dungeon and did you get Undaunted Credit? If so, that is the most important part of the thing.
If your trying to collect a Pledge reward from the Undaunted enclave, same thing with the relog, but you can ignore the part of the dungeon spawns as you are not in the dungeon.
Enjoy the game, life is what you really want to be worried about.
PakKat "Everything was going well, until I died"
Gary Gravestink "I am glad you died, I needed the help"