I upgraded to the same version after seeing your message and this fixed the issue for me too. I had to go one last time in settings and set it to Sonnet but now all tabs use Sonnet.
But it seems I have a much bigger issue with this version. The usual network errors that I always had (they were always there) started not being retryable. Usually when I pressed the retry button it would disappear and pop back up after a second or five. Until eventually after multiple tries it worked. But now clicking the button does nothing. I don’t know if it’s doing something in the background but it doesn’t seem so and I tried pressing it many times and still got no answer from Leo. It just stays there saying “Network error”. I’ll post this on the other thread for the network errors too.
EDIT: Reverting to 1.71.123 does not re-break the settings.