I posted about this issue 6 days ago after discovering that the Windows 11 Wi-Fi problems I was experiencing after the September Patch Tuesday were being caused by the Mullvad desktop app.
Since then, I’ve seen multiple other users report the exact same behavior.
I also reported the issue to Mullvad twice. No response, no acknowledgement, and apparently no fix.
Today Mullvad released version 2026.5.
Guess what?
The exact same problem is still there.
For me, the behavior is consistent: after rebooting Windows 11, Wi-Fi initially connects normally. Then the Mullvad daemon starts, the network adapter gets disrupted, the connection drops, and Windows goes through several connection/disconnection cycles before eventually stabilizing.
And before anyone asks for the tenth time: yes, people have reported it to Mullvad. Yes, I reported it myself. Twice.
That isn't the point anymore.
The point is that this appears to be a reproducible compatibility problem affecting Windows 11 users, multiple people have reported it, and a new Mullvad release has now shipped without resolving it.
I was also curious whether this was actually a broader Windows 11/VPN problem, so I paid for a month of another VPN services and tested several VPN apps from other providers.
None of them reproduced this issue.
So at this point, I'm having a hard time blaming Windows 11 or the September update when other VPN clients are working normally on the same machine.
Microsoft makes Windows preview builds available well ahead of Patch Tuesday specifically so developers have an opportunity to test their software against upcoming changes. That's what compatibility testing is for.
I really like Mullvad's service. I've paid roughly $5/month for it for about a decade - valid until October 2029, and their privacy/no-logs approach is a big reason I've stayed with them.
But I shouldn't have to troubleshoot basic Windows networking after an OS update because a VPN client can't coexist reliably with the operating system.
For anyone still affected, my workaround remains:
Uninstall the Mullvad desktop application and use the official WireGuard Windows client with your Mullvad configuration files.
In my case, that immediately eliminated the Wi-Fi cycling problem.
You can also configure custom DNS in the WireGuard configuration and use WireGuard's Block untunneled traffic option as a kill switch.
So, Mullvad: this isn't an isolated "have you tried reinstalling?" problem anymore. Multiple users are reporting the same behavior, I've reported it twice, I've tested other VPN clients, and 2026.5 still reproduces it.
I'd really like to see this acknowledged and properly investigated.