20.04 – Port selection not possible in Arduino IDE on Ubuntu20.04

I have upgraded to 20.04. Arduino IDE loaded with snap install arduino, as suggested (version 1.8.3). The Port selection item cannot be selected. As suggested in other posts, I have done
sudo usermod -a -G dialout $USER

Actually, this added dialout in groups, I did reboot, dialout is still in groups, but still Port cannot be selected, and, of course, I cannot upload anything on Arduino.

Thank you!