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 a Mobile Game Losing Its Bluetooth Controller After Screen Lock

Q: What causes a mobile game losing its Bluetooth controller after screen lock?

When the device sleeps and the app is paused, the OS tears down the input device session, and on resume your game keeps using the stale device handle instead of re-scanning.

Quick answer: Re-enumerate connected controllers in your app-resume or focus-gained callback and rebind input to the current device instead of the cached one.

If a Bluetooth pad stops responding after the phone locks and wakes, the input session was reset while paused. Re-scanning on resume fixes it. Here is how.

How to fix it

1. Re-enumerate on resume

In the activity/app resume callback re-query the connected input devices and pick up the controller again. The handle captured before sleep is no longer valid.

2. Clear cached device state

Drop any stored device id or input object on pause and rebuild it on resume so stale references cannot silently swallow input after wake.

3. Handle the reconnect event

Subscribe to the platform's device-added notification so a controller that reconnects a moment after wake is bound as soon as it appears.

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.

The bug you can't reproduce isn't gone — it's just invisible until you capture it from the player's device.