Cannot connect with imported VPN configurations anymore, despite having no issues last version

[apparatus]

@gimmy

Last version is the only one that ever actually worked finally, but it’s broken again.

Are you talking about last Qubes OS version?
It worked for you in Qubes OS 4.1 but doesn’t work in Qubes OS 4.2?
If yes then it’s most probably the firewall issue:

@system

Known issues in Qubes OS 4.2.0

DomU firewalls have completely switched to nftables. Users should add their custom rules to the custom-input and custom-forward chains. (For more information, see issues #5031 and #6062.)

If you have any firewall rules in your VPN config file then you’ll need to convert them from iptables to nftables.
You can see some examples of such conversion here:

Comparing tasket:master...1cho1ce:replace-iptables-with-nftables ·...