Chromecast Audio Group Missing

Hello Community

After some updates, I realised my Cast Group is missing. HA and Cast are in a different subnet, so I configured them manually. Avahi is active on the router and mDNS works as Chrome can communicate with the group from another device in another subnet.
Is there an option to configure the group manually? Or has anyone any idea what could cause the problem?

Cheers, Luke

Tracked under issue #13530:
https://github.com/home-assistant/home-assistant/issues/13530