I found the culprit thanks to your very helpful instructions: the network-manager service was running in the VM.
It happened because I did first test my VPN with the instructions (https://www.qubes-os.org/doc/vpn/) following the "Using NetworkManager" section as a quick test, to only later set it up without it. Thanks again. I hope this thread will be useful for others facing similar problems. -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to qubes-users+unsubscr...@googlegroups.com. To post to this group, send email to email@example.com. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/f35d90b9-2632-4f91-afff-3e1f8ac26302%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.