If not all speakers are visible in the Google Home or Spotifyapp, your phone/source may be connected to another network or not all the speakers may be set to the same network. In this case, we recommend you do the following:
Delete the Google Home app from your phone or tablet.
Then reset your speakers and/or soundbar
To restore the factory default settings, select ‘Options’ > ‘Factory Reset’ on the display of your speaker or soundbar (see Q&A for all reset procedures).
All settings will be deleted and you will now be ready to reconfigure your product in the Google Home app.
Now reinstall the Google Home-app.
If you have a standard provider router with a 2.4 GHz and 5 GHz home WiFi network, we recommend that you separate these two bands by giving the 2.4 GHz and 5 GHz networks each a separate SSID (network name) and password.
To do this, you must log into the modem. If you are not sure how to do this, we recommend you contact your Internet provider, who will be able to assist you with this over the phone.
In the network section there's an article witch explains how this can be done manually. Afterwards, be sure to connect the phone or tablet to the faster 5 GHz home WiFi network before you run the setup again. If you have made changes to your network settings, make sure that all your devices are registered on the ‘new’ network and make sure to forget any other networks with which your phone/tablet was configured to connect automatically.
Also please check out the article about preventing interference.
NOTE: In some cases it may help to change the DNS server to the DNS of Google (8.8.8.8) to optimize the connection with the Google platform. When using extenders/repeaters or other external WiFi equipment (besides the standard provider router) please fill in the contact form here for advise.