Quick answer: Compute the final applied damage in one place, return it from the damage function, and use that returned value both for the health change and the popup.
If the number that pops up says 100 but the enemy lost 60, the popup is reading a different value than the health system. Sharing the final value fixes the mismatch. Here is how.
How to fix it
1. Return the applied amount
Have ApplyDamage return the actual HP removed after mitigation, crit, and clamping, rather than recomputing it in the UI.
2. Spawn the popup from that value
Pass the returned applied damage into the floating-number spawner so the displayed number is exactly the health change.
3. Show crits distinctly
If you display crits differently, flag the crit on the same result object so the popup styling and the number both come from one source of truth.
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.
The bug you can't reproduce isn't gone — it's just invisible until you capture it from the player's device.