Mullvad VPN GUI not working on fresh Elementary OS 8 install

[sees7ern]

Is it a bug?

• I know this is an issue with the app, and contacting Mullvad support is not relevant.

I have checked if others have reported this already

• I have checked the issue tracker to see if others have reported similar issues.

Current Behavior

Manually installed Mullvad VPN on a fresh install (incl all recent security and system updates) of Elementary OS 8 Circe using the most recent .deb (2024.8 / Intel x86_64 / Ubuntu/Debian / Stable), downloaded directly from the Mullvad website. Mullvad VPN works as intended via CLI. The GUI does not open in any shape or form, neither in the Classic nor the new Secure session format of Elementary OS 8. Reinstall of the app comes to the same. Installing via curl is not an option as it provides an error message that the repository does not have a Release file. GUI via manual install worked fine on Elementary OS 7.1.

Expected Behavior

GUI opens upon click on installed app.

Steps to Reproduce

1. Install Mullvad VPN manually on Elementary OS 8 Circe
2. Open installed app via GUI

Failure Logs

No response

Operating system version

Elementary OS 8

Mullvad VPN app version

2024.8

Additional Information

Using a Starbook Mk V https://de.starlabs.systems/pages/starbook-mk-v-specification?shpxid=bf7c0057-7017-4295-ae5b-6a8dfae591f0

[sees7ern]

adding to the above

when running

/opt/Mullvad\ VPN/mullvad-vpn

or

/opt/Mullvad\ VPN/mullvad-vpn --disable-gpu

output is (respectively)

[18878:1226/225531.632870:FATAL:setuid_sandbox_host.cc(158)] The SUID sandbox helper binary was found, but is not configured correctly. Rather than run without sandboxing I'm aborting now. You need to make sure that /opt/Mullvad VPN/chrome-sandbox is owned by root and has mode 4755.
Trace/breakpoint trap (core dumped)

or

[19289:1226/230615.126364:FATAL:setuid_sandbox_host.cc(158)] The SUID sandbox helper binary was found, but is not configured correctly. Rather than run without sandboxing I'm aborting now. You need to make sure that /opt/Mullvad VPN/chrome-sandbox is owned by root and has mode 4755.
Trace/breakpoint trap (core dumped)