Hi @rasmuskjaer.

Welcome to the Sonos community and thanks for reaching out to us. I understand your situation and would want to help out.

I would like to recommend the following guide to try if the Sonos App can still locate your Sonos Play 5. This guide is about speakers missing from the Sonos app. 

I would like to suggest some basic troubleshooting steps and check what would be the possible results.

• Can we try rebooting the router? (unplug the router from power and plug it back after 10-15 seconds)
• Once the internet connection has been restored, let us reboot the Sonos device connected to the router via ethernet cable (if applicable). If not, Let us reboot the Sonos device nearest to the router. (unplug the Sonos device from power and plug it back after 10-15 seconds).
• After the Sonos device displays a solid white light, let us try to reboot the next Sonos device until all of them are finally rebooted.
• Then, we may want to consider relaunching the Sonos app. ( Force close the Sonos app from the running background and re-launch the Sonos app).
• Let us check if the Sonos app would now reconnect to the existing Sonos system.
• If the Sonos app still has the same problem, we may want to try rebooting the mobile controller.  (turn it off and turn it back on).
• We may also want to consider trying a different controller to check if we may have a different result. (different mobile phone)
• We may want to consider submitting a diagnostic so we can further check what is going on.

After following the recommendations above accordingly and still have the same issue, I would like to recommend provid9ong some details so we can check our internal articles to see what might be causing this issue.

• Router make and model.
• Wifi extender/Wifi Booster/Wifi repeater make and model if applicable.
• Secondary router make and model if applicable.
• Mesh system like Deeco, Ubiquity, Google Mesh, or eero mesh system if applicable.
• Other devices connected to the router (wired connection).
• Other devices connected to the Wifi network (wirelessly).

I hope this helps.

Please let us know if you still have further questions or concerns. We are always here to help out.

Thanks,