Quick answer: Reset to the stored original scale before each punch and kill any running punch tween, so every press punches from the same baseline.
Mash a button with a punch-scale effect and it slowly bloats or shrinks because each punch started from the half-finished state of the last. Anchoring every punch to the stored rest scale and cancelling overlaps keeps it consistent no matter how fast you press.
How to fix it
1. Reset scale before punching
Store the rest scale once, then set the transform back to it (or pass it as the punch's base) before starting each punch so drift cannot accumulate.
2. Kill the previous punch tween
Call transform.DOKill() or cancel the prior punch before starting a new one so two punches do not stack and compound the scale offset.
3. Use a punch helper that returns to base
DOTween's DOPunchScale returns to the value it started from; just ensure that starting value is the rest scale, not a mid-punch value.
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 Unity 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.
Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.