Turns out GNOME Tweaks caused this. I restored default settings in GNOME Tweaks, then I logged out, and in a tty, I reinstalled ubuntu-session and every part of the yaru theme:
sudo apt purge ubuntu-session yaru-theme-gnome-shell yaru-theme-gtk yaru-theme-icon yaru-theme-sound sudo apt install ubuntu-session yaru-theme-gnome-shell yaru-theme-gtk yaru-theme-icon yaru-theme-sound then after logging in, all the themes were applied correctly. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1798984 Title: Yaru theme installed but not enabled by default nor available after upgrade to Cosmic To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/yaru-theme/+bug/1798984/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs