Q: Why do I have to enable Google Password Manager as an additional provider in order to make it work on Android?

All internet connections into and out of your Linux device will now be blocked unless a VPN connection to a Proton VPN server is active.

If I understand correctly, before version 4.2.0 (that includes the Advanced setting), the kill switch wasn’t active until you opened the ProtonVPN program. So if you restarted you PC, it was connecting to the internet without going through the VPN tunnel, so your traffic was somewhat exposed.

Now, with the new permanent kill switch, there’s no internet access without running ProtonVPN.