debounce filter vs glitch filter
A bounce is a reversal of state that occurs immediately after a deliberate transition.  A glitch is a spurious change not associated with a deliberate transition.  Both are temporary and brief, but when filtering bounces you want to acknowledge the very first transition as early as possible and ignore subsequent changes until the end of a hold off period, and when filtering glitches you want to ignore the very first transition until the end of a timeout when you can be confident that it's deliberate.

Sadly far too many debouncers are implemented as glitch filters, resulting in buttons that are unnecessarily slow to respond.

That's what the difference is, but I doubt that that helps you with your problem.