What period is required to trigger a pin pulled to GND?

I’m using an imp006 on an internet connected air rifle target. According to my 'scope, when the pellet strikes the plate, depressing a button, the normally HIGH pin is pulled to ground for 15ms, however, the pin never triggers its callback. It works just fine if I press the pin by hand. The pin I am measuring on is XT.

NM, the problem here is the “BUTTON” library is doing some kind of debounce magic? I configured the pin without it and it registers just fine.

I was able to get the library to trigger the .onRelease function, but it never triggers the .onPress. This works for my purposes, but could be noted with the Library.

Yes, debounce lib is specifically intended to filter out what look like switch bounces - hence you’d only see the release, not the press, for a short enough event. See the library source.