How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix AR Anchors Drifting After Tracking Recovery in Unity AR Foundation

Q: What causes AR anchors drifting after tracking recovery in Unity AR Foundation?

Content is parented to a plane or a fixed world pose instead of an ARAnchor, so it does not get corrected when the tracker relocalizes.

Quick answer: Parent placed objects to an ARAnchor created via the ARAnchorManager so the AR subsystem updates their pose when tracking relocalizes.

When AR tracking is briefly lost and then recovered, the device's world origin can shift. Objects pinned to a raw world transform stay at the old coordinates and appear to drift. Attaching them to an ARAnchor lets the AR system re-anchor them to the real environment after relocalization.

How to fix it

1. Create a real anchor

When placing content, create an ARAnchor at the hit pose via ARAnchorManager (or attach it to the hit plane) instead of just setting a transform.

2. Parent content to the anchor

Make the spawned object a child of the anchor's transform so the subsystem can correct its pose during relocalization.

3. Re-anchor sparingly

Avoid recreating anchors every frame; create one per placed object and let the system maintain it to keep drift minimal.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every mobile error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Reproduce it once with full context and the fix writes itself. The hunt is the expensive part.