Help ePSXe: controller is not working

Hi guys!
I downloaded ePSXe v.1.9.25 and I configured it. It plays correctly any game using the keyboard.

When I use the PSX controller, it works at the beginning but it stops working after a couple of minutes.
If I return to the ePSXe main menu (pressing ESC button) and continue the game (using "Run" --> "Continue"), my controller starts working again for another couple of minutes.

Can anyone help me with this problem?
Thanks