What causes a jump buffer triggering two jumps from one press?

You leave the buffered-jump flag set after consuming it, so on the next physics frame the still-set flag triggers a second jump before the buffer expires.

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 Jump Buffer Firing Twice on One Button Press

Quick answer: Clear the jump buffer immediately when you spend it on a jump, and only set it on the rising edge of the press, not while the button is held.

Jump buffering should let a press land slightly early count when you touch ground, but a buffer you forget to clear fires again next frame. Consume it atomically. Here is how.

How to fix it

1. Set the buffer on press-down only

Record the buffer timestamp on the rising edge (just_pressed), not every frame the button is held. Holding jump should not keep refilling the buffer.

2. Clear the buffer when you jump

The moment a buffered jump executes, zero the buffer timer in the same frame. A leftover non-zero value will satisfy the buffer check again on the next tick.

3. Decay the buffer over time

Decrement the buffer timer each frame and ignore it once it hits zero. This keeps a stale early press from being honored several frames later when it no longer feels intentional.

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 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.

Most of the time the fix is small. Seeing the failure clearly is the part that actually costs you.