As the title suggests, doing the Legacy quest for Storm Kings Thunder that requires you to complete 5 quests - none of the Lonelywood quests available at the tavern count. At least none of the ones I did: kill goblins in lumber area then light fires, check boxes on the docks, collect animal hides, collect weapons, kill trolls and burn stuff in their camp, cut down big trees to make ship masts. Given that, I think it is an Lonelywood wide issue.
The SKT kill 100 legacy quest and do heroics legacy quest both work correctly in that area.
If you can't stand on a chest, it is a mimic!