Do treasure chests respawn, and can another player take your reward?

The developer describes discovered chests as openable once per character. Another player opening one does not remove your own opportunity. Search for chests you have not claimed instead of waiting beside the same chest for a personal reward reset.

What the ownership rule means

A chest can be visible to other players without being a race for a single shared reward. XLGAMES specifically says that chests and other discovered objects can be opened once per character, so finding one later is still worthwhile.

That statement does not supply a timed reset schedule, a server-maintenance refresh or a daily farming route. Do not assume changing channels restores your character's claim. Keep a note of what this character has already opened if you are revisiting an area.

What you can find

The progression overview names equipment and rare crafting recipes among chest rewards. It does not promise that every chest contains both, or give a universal loot table. Read the actual item and recipe descriptions after collecting them before deciding what to keep or craft.

Chest rewards, Coilstone Trait Points and Nui Tear HP upgrades are separate reasons to explore. Finding equipment in a chest does not mean you also gained the points needed for a locked weapon skill.

Look beyond the main path

The developer describes both obvious chests and hidden discoveries, including the example of looking behind a waterfall. This supports checking side paths and landmarks, not assuming every waterfall contains a chest. Observe the area and return when you can reach a discovery safely; this guide does not invent map coordinates.

If a chest will not interact

First distinguish an already claimed discovery from an interaction that never completes. The November 7 maintenance improved some gathering-object and NPC interaction problems; it does not announce a reset of previously claimed chests or a fix for every chest failure.

Update the game, note the location and record whether this character opened it before. If a repeatable interaction problem remains, provide the prompt, location and what happened to support. That is more useful than repeatedly changing channels on the assumption of a guaranteed refresh.