Hi @Gloupz, welcome to the Sonos Community!
Sorry to hear you’re having issues casting music to your system. This is definitely a strange issue you’re running into, and I can’t see any information regarding any similar issues.
How are you playing music to Sonos system? You mention casting, but are you just using the Sonos app, Airplay, a music service’s direct connection? If you have the option to use one of the others, I’d suggest trying that so we can narrow down what does work and what doesn’t, and so I can give the appropriate troubleshooting steps. It also doesn’t hurt to reboot your system by powering off your Router, Sonos Speakers, and device with the Sonos app installed for one to two minutes if you haven’t already.
If the issue is that you can’t play any audio to your system while the One SLs are paired, then I’d recommend contacting our support team for further troubleshooting, as they have the necessary tools available to look into your system and resolve this issue for you.
I hope this helps!