enable firewall button goes back itself to dissable firewall

When trying to enable the firewall in a new installation of linux mint cinnamon 19.3, I cannot get the enable firewall button to stay enable, it goes back itself to disable every time I tried, after a few seconds. I tried closing right away the menu after enabling but when I reopen is disabled. I also tried restarting the machine and is always disable. Any hint on how to fix this? This is my first try at linux... Thanks! Ale