Hi @Ldubos! Thanks for posting to community.
Let's try some troubleshooting for your Onkyo receiver.
I've removed the device association with your Pandora account. When this takes affect, it will log you out. I'd also recommend disconnecting your receiver from the power source, wait 30 seconds, and then plug it back in.
Once you power back on, log back into Pandora and try once more. Let me know how it goes.