Ben here with the support team, thanks for taking the time to write in! Since a few days have passed, I wanted to check in on this issue. Are you still seeing delays in the artist image on your Chromecast display?
If so, the first step I would suggest is to simplify your network setup, and hardwire your core directly to your router. With that, simplify your external display via Chromecast as well, and see if your issue persists.
If you haven’t yet, please power cycle your network and give your core a hard reboot as well.
I was waiting to see if this issue happens again, but I haven’t seen this issue recently since I first reported it. Not sure what caused it or fixed it. But I’ll try your suggestions if it happens again,