This solved the problem for me, after the last update
- Before you can add Matter-based Thread devices, your phone needs to know the credentials of your newly created Thread network.
- To share the credentials with your Android phone, open the Home Assistant Companion app.
- In the Companion app, go to Settings > Companion app > Troubleshooting, then select Sync Thread credentials.
- Follow the instructions on screen.
- Result: You will see a confirmation stating that Thread credentials from Home Assistant have been added to this device.
- To add Matter-based Thread devices, follow the steps on Adding a matter device to Home Assistant.