Hi @CoenSanderink,
Thank you for reaching out to the Sonos community and for your detailed post describing your concern. Let me help you with this.
The diagnostic shows that your Sonos Beam is detected as a dropped room and getting low wireless signal strength from the router. This could be the reason why you can’t add your rear speakers and sub in a home theater setup. Also, detected interference in your wireless network that may be caused by wireless congestion or low wireless range.
Let me suggest the following steps to see if this would work for you.
- Reboot your Sonos Beam
- Unplug your Sonos Beam from the power
- Wait for 30 seconds before you plug it back in
- Check on the Sonos app is your Beam is showing
- Try to add your rear speakers as surround and add your sub
- If the issue is the same, proceed to the next step
- Sequential reboot to refresh your network and all your Sonos devices connection.
- Unplug your network devices (modem, router, any wireless access points on the network) from the power and wait for 60 full seconds before you plug it back in.
- Once the router is back online, unplug all your Sonos devices from the power. Please wait 15 seconds before you plug back them back in.
- Force close the Sonos app from your iOS or Android device.
- When the status light on your Sonos speakers are solid white, get back on the Sonos app and check if you're connected.
- Check the status lights on your Sonos speakers, they should have solid white light an indicator that your Sonos is connected.
- Try to add your rear speakers as surround and add your sub
- Hardwire one of your speakers to your router.
- Try to add your rear speakers as surround and add your sub
Let us know how you get on with the advice above. Please run another diagnostic report and include the confirmation number in your response.