Hi @Mw28
Welcome to the Sonos Community!
If your iOS Sonos app works without issue but your Android app does not, then there are three possible reasons for things going wrong - third-party software on your Android device causing problems (VPN software would do this, for example), the Android device is connecting to your network differently (through a different Access Point, for example), or it just needs a reboot.
If restarting your Android device does not help, I recommend you get in touch with our technical support team who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports.
@ratty makes a good point, however - the above advice relates to the Sonos app in particular. If you are not using it, or the issues you refer to are seen on other apps, it would help to know which app is having issues, but I still recommend that you call in.
I hope this helps.