Home Assistant Cloud by Nabu Casa not linking in Google Home App

After migrating my setup of Home Assistant, I’m failing to link my Home Assistant instance to Nabu Casa in the Google Home app.

First off, my setup. I’m running Home Assisant on an Intel NUC with a static IP and Home Assistant running as a VM on VirtualBox using NAT-networking through port forwarding :8123. Home Assistant Core 2022.5.5 & Home Assistant Supervisor 2022.05.2. I am subscribed to Nabu Casa.

When trying to link the service through the Google Home App, I select Add New Home Assistant Cloud by Nabu Casa, I am send to a link, I allow access, and then it says “Linking your Home Assistant Cloud by Nabu Casa account”. That takes a couple of seconds, stops and nothing changes.

I have disabled ipv6 on my Supervisor (as per Troubleshooting) and also made sure I have no http configuration and no devices exposed (as per Google Assistant - Home Assistant).

No luck so far. Any help?

Edit: Tried some additional stuff.

  • Tried linking again with the VM running on a Bridged Adapter with port forwarding to both the new IP of the Home Assistant VM and of the Host
  • I have unlinked, linked, cleared the cache of Google Home app, of Chrome, signed in and out
  • I have tried linking through the mobile Google Home app on an iPhone and Android
  • Finally, I paused my Home Assistant VM and restarted my previous install (Home Assistant on Hyper-V on my main laptop)

Linking failed in all cases. I am very much running out of ideas!