Hi,
the input pullup is about 150k (read datasheet). this gives a time constant of 150k x 100nF = 15ms. But only on rising edge.
The falling isfast, because there is no current limitng resistor. Maybe connect a 1k in sereies to ech switch.
For further discussion please attach a schematic.
***
Microswitches never cause a hanging microcontroller.
In many cases "hanging" is a software problem, or a PCB layout/wiring problem.
Like connection of RESET pin. Missing or wrong or wrongly wired supply capacitors. Missing ground plane.
Klaus