I only use #MullvadVPN and it works for me - unlike #protonVPN.

The main issue with proton is that I cannot exclude some apps. Usually I have a 3 browser setup: Tor Browser for general reading, Mullvad Browser with VPN for services where I login and Firefox for sites without VPN (like online banking). Just create a *.desktop file to run "mullvad-exclude firefox" and it works.
With Proton I would have to setup a VM for non-vpn browsing.