Hi @ss0089
Welcome to the Sonos Community!
Do I understand you correctly in that regardless of what you see in the app, it makes no difference to the sound heard and the subwoofer plays as it should even when the settings are missing? If that is that case, then contrary to what one might initially assume, this might just be a communication issue between the app and the Amp, rather than some kind of subwoofer detection issue on the Amp.
The next time you can’t access the subwoofer settings, please immediately submit a support diagnostic and then, when convenient, post the given number here and I’ll take a look for you. Once you have submitted the diagnostics, please reboot your router by switching it off for at least 30 seconds to see if that happens to bring the subwoofer settings back in the app when the system is running again. If this does help, it’s possible you’ll just need to reboot the router a few times a year (which I recommend doing anyway).
You are welcome in advance.
The suggestion to reset the router is absurd. I have experienced this since day one with my Sonos amp too. Different iOS devices, different operating systems, every Sonos app update, different network (Netgear managed business class currently) and even switching from Xfinity to municipal fiber - the one consistent thing is this setting shows up intermittently. Sensing an RCA connection is very rudimentary and holding fail (I work for an AV manufacturer and have been in the industry for over 30 years). This is 100% an intermittent bug.
