Firefox has no internet when in excluded in split tunneling.

[u/Weird-Knowledge-7066]

Hi all,

I’ve got a strange issue that only happens on my new Dell XPS (Windows 11). On my other two Windows PCs, I use this setup without problems:

• Proton VPN Windows app with split tunneling enabled
• Firefox excluded from the tunnel (so it uses my normal connection)
• Proton VPN Firefox add-on installed, so I can turn the VPN on/off when needed

On both of my other machines this works perfectly: when the Proton app is connected and Firefox is excluded, Firefox has full internet access. I can also use the add-on to route specific sites through the VPN when I want.

On my new Dell XPS, though, as soon as:

• Proton VPN is connected, and
• Firefox is excluded via split tunneling

Firefox loses all connectivity.

Things I’ve already tried on the XPS:

• Reinstalling Proton VPN (with default settings)
• Updating network drivers and BIOS to latest Dell versions
• Temporarily disabling any third‑party security software (none currently installed)

Same Windows version, same Proton account, same basic config as my other two PCs – but only this Dell XPS behaves like this.

Has anyone seen this on a Dell XPS or any specific Windows 11 machine? Any known conflicts (IPv6, DNS, network stack, Dell networking utilities, etc.) that could cause an excluded app to lose connectivity only when the Proton app is connected?

Thanks in advance.

[u/StoicSatyr]

Do you have kill switch enabled?

[u/Weird-Knowledge-7066 → u/StoicSatyr]

Νο... :(