That's a "feature" on Gnome 3.25 but we acknowledge it is inconsistent and imperfect (see also bug 1712992). I'm hearing that either upstream or Ubuntu is going to make a decision/change on the appearance soon.
** Changed in: gnome-shell (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1715649 Title: gnome panel is only rendered correctly when a window is touching it To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1715649/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs