Ok, yesterday it did work all day, but today at 18:04 (CET) it stopped working again (despite the new DNS servers in my router). At 19:30 it worked for a few minutes, but now (19:42) it stopped working again.
Totally unpredictable behaviour.........I give up and enjoy my Harman Kardon (Citation Towers, great speakers by the way!).
So for me in Germany all devices from different manufacturers work without problems.
For my BS2 mk1, the Chromecast version is still the same as yours and it works here at any time of day completely without issues ...?
@HAWK
Just one last idea if you still feel like trying (since you have other good speakers :))
1.
I also had DHCP disabled in the B&O app and gave my BS2 a static IP (outside my routers DHCP range!), see screenshot below, and changed the DNS server.
Whether that also makes an improvement in this case, I do not know.
2.
If this is not too cumbersome and annoying in your case, you could try a daily reboot of your router.
Or better just a reconnect.
If your router, like my Fritzbox, offers this possibility. With a reconnect you get a new IP address in seconds and this solves various kinds of problems. I can well imagine that it also would help in this case.
But if not, then I'm out of ideas and can't think of anything else to try :)