expo: Error starting tunnel: Error: Error: failed to start tunnel

I’ve been happily developing all day through the Expo tunnel feature until I restarted my project. I receive a valid exp:// link, but the device says “No experience can be found at …”. I have restarted my Expo XDE and tried starting through the exp CLI. I tried clearing the Expo XDE cache to no avail.

λ exp start --tunnel --dev
[exp] Making sure project is set up correctly...
[exp] Your project looks good!
[exp] Using project at <my project path>
[exp] Starting React Native packager...
[exp] Scanning 676 folders for symlinks in <my project path>\node_modules (17ms)
[exp] Loading dependency graph.
[exp] Running packager on port 19001.
[exp] Expo is ready.
[exp] You can scan this QR code:

<omitted>

[exp] Your URL is

exp://<my random url>.mariotacke.mobile.exp.direct:80

[exp] Logs for your project will appear below. Press Ctrl+C to exit.
[exp] Dependency graph loaded. 

The Expo XDE client log shows:

5:00:20 PM Starting React Native packager...
5:00:21 PM Scanning 676 folders for symlinks in <my project path>\node_modules (23ms)
5:00:22 PM Loading dependency graph.
5:00:22 PM Running packager on port 19001.
5:00:22 PM
5:00:26 PM Error starting tunnel: Error: Error: failed to start tunnel
5:00:26 PM Project opened! You can now use the "Share" or "Device" buttons to view your project.
5:00:34 PM Dependency graph loaded.

Any idea how to further debug this? It looks like the packager starts properly and the tunnel URL gets created.

I ran a netstat to look for any orphaned process that blocks the port, but I got nothing.

System: Windows 10 SDK: 17.0