Timeless isle chests

Hello!
I've tried to look for the answers for my questions in the game but nobody gave me clear answers.. so i have a few questions. Do "moss-covered chests" on timeless isle respawn or they can be opened only once per character? Somebody told me that they respawn in like 10-20mins but im sitting there all day and none of them respawned. BUT on my other character they are magically there on every spot. So are they "character binded" or can be opened by everyone?(if they do respawn of course)
Have a nice day!

Moss-covered chests can be opened once per character. Same as blazing and smoldering chests. Skull covered, sturdy and rope bound chests respawn weekly.

That said, it's possible for others to open chests before you which'll mean you'll need to wait 10-15 minutes for them to spawn again so that you can open them as well.