Ok so looks like I'm not the only one .
I noticed a few days ago that I could no longer connect Spotify to any of my Wiim devices throughout the house. I Use wiim as multi-room running several Wiim amps to ceiling speakers and then ultras/pro plus to hifi set ups.
i too noticed 'Google cast' now next to my devices in the Spotify devices selection screen which as of last week were never there before...click on the device and it just 'hangs' on connecting and never actually connects. I too, do not have Google cast enabled and I've never used it so not sure why it appears there now all of a sudden.
From reading above I guess my Spotify app must have auto updated to this new, non compatible with wiim Edition.
I've had several back and forths with wiim technical help, all of their solutions have failed to resolve the issue.
I'm Running an Samsung galaxy s21
... wonder if I am going to have to finally be forced to get that phone upgrade I've been putting off for years to resolve this !?