Hi @Herr, welcome to the Sonos Community!
I’ve tested on my system and have both ‘Play Next’ and ‘Add to End of Queue’ options in the Sonos app.
First you’ll want to make sure everything is up to date, so the Sonos App, your Sonos speakers, and your Android Phone OS.
If everything is up to date and you still aren’t seeing those options, try restarting your phone or testing with another device. If another device works, check if you meet our app requirements.
You could also reset or re-install the Sonos App. Your system settings are saved on the speakers and the app is just a remote to the system, so a reset/reinstall of the app wont cause any issues with your system.
I hope this information helps!