`multipass launch`: `launch failed: Remote "" is unknown or unreachable.` in ubuntu 25.10

**Describe the bug**
Hi folks, I'm hitting the long running issue people sporadically report with `multipass launch` of `launch failed: Remote "" is unknown or unreachable.` I'm using `1.16.1` from `latest/stable`.

This is on a reasonably fresh install of Ubuntu 25.10 on my corporate laptop, after installing multipass. Running with `-vvvv` I (sometimes) get some more information:

I've seen reports of this in the last month in [engineering onboarding](https://chat.canonical.com/canonical/pl/5sdb8adgpffofx7iiitd4fie1o) too. Both the onboarder and myself found the related [issue](https://github.com/canonical/multipass/issues/3464), which was closed some time ago (though I see there's another open issue linked there).

The fix `multipass` implemented seems to be exponential retries, but the command exits very quickly for me, so I wonder if that's happening. I've also tried to documented workarounds of restarting the snap, restarting `multipassd`, and waiting 15 minutes after reboot, but no luck. Any ideas?

**Logs**
```
[2026-02-23T19:37:33.047] [trace] [url downloader] Found https://codeload.github.com/canonical/multipass-blueprints/zip/refs/heads/main in cache: true
[2026-02-23T19:37:33.049] [debug] [blueprint provider] Loading "anbox-cloud-appliance" v1
[2026-02-23T19:37:33.049] [debug] [blueprint provider] Loading "charm-dev" v1
[2026-02-23T19:37:33.050] [debug] [blueprint provider] Loading "docker" v1
[2026-02-23T19:37:33.050] [debug] [blueprint provider] Loading "jellyfin" v1
[2026-02-23T19:37:33.050] [debug] [blueprint provider] Loading "minikube" v1
[2026-02-23T19:37:33.050] [debug] [blueprint provider] Loading "ros2-humble" v1
[2026-02-23T19:37:33.050] [debug] [blueprint provider] Loading "ros2-jazzy" v1
launch failed: Remote "" is unknown or unreachable.
```

[multipass-logs-2026-02-24-1040.txt](https://github.com/user-attachments/files/25515072/multipass-logs-2026-02-24-1040.txt)

**Additional info**
- OS: Ubuntu 25.10, authd installation
- CPU architecture or model: --
- `multipass version`: 1.16.1