My switch does not turn on when the taps are running even when the water has stopped coming out. I usually have to push the contacts together to get it to work

Probably blocked pipe or tubing to the pressure control switch.
Turn off power, open faucet to relieve pressure, remove switch from piping or disconnect tubing from tank to switch. Inspect and clean inside pipe and opening to switch.

While you have the switch off, replace it. They are relatively cheap (25 bucks) and it's not worth the headache to remove the switch, clean out the pipe, hook everything back up, and turn on the breaker, only to find out that it was the switch all along and not the pipe.

But HK is entirely correct. The little pipe can get clogged and cause the switch to become sluggish. Check it out. Replace them both.