The official Lost Ark forums are plagued with Buried in Flowers quest issues, the finishing quest on the Azure Winds Island. That quest is required to complete the Collectives Challenge List named “On Azure Winds. Additionally, it will grant you the Azure Wind Island Soul. Well, let’s see if we can fix what’s not working.
I guess you have completed all of the puzzles on that island (because there is a plethora of them), including the one related to the Shangra island (the one with the egg on Azure Island), then makes sure you pay attention to the following.
There are 2 quests that are without an indicator that become active after the whole Shangra questline is finished. They can be activated just the same as the others, by interacting with the horses. With that said, I would advise you to check the locations of the Final Riddles. They are highlighted in the map below:
For a close-up look of the quest giver and intractable horses, check out the images below:
After you complete these and the final riddle, you should see a quest available exactly in the middle of the map. For a better overview, check out the image below:
If you do not have these puzzles done, then I’d suggest you take a look at the picture below and go through all of them.
If you’re still having trouble, check out this Maxroll guide and go over all of the spots, including the quest with the egg, which also asks you to go to Shangra Island.