Eden-DAoC

Recently noticed that if I killed the Spindelhalla bosses I would get credit for the Trollheim Mytherian quest.

Killed Te'bui and Smarta in Spindel and got Trollheim Explorer credit for Uppat and Nedat Gungledar.

I can only assume that if I soloed all the Spindel bosses ide get credit for all the corresponding Trollheim bosses

This is just a visual bug with the quest journal. You wont actually finish the opposite quest or get the reward. Visual bug should be fixed when devs are able to do a deep dive.