I can confirm this issue. Many modern GNOME applications are affected. I have seen this behavior with Nautilus, GNOME Calendar and GNOME Software (see attached screencast).
** Tags added: eoan focal ** Attachment added: "Screencast from fresh installed system Ubuntu-MATE 20.04 LTS _Focal Fossa_ - Alpha amd64 (20200119)" https://bugs.launchpad.net/ubuntu-mate/+bug/1854383/+attachment/5321571/+files/gnome-software.gif ** Also affects: gtk+3.0 (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1854383 Title: Extra window decorations are created on windows with client-side decorations. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-mate/+bug/1854383/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
