I am not sure exactly which commit fixed the problem, but I suspect it's an update in Yaru itself. Possibly one of those:
https://github.com/ubuntu/yaru/commit/4a6484deaa19c284344923efb1ccdc1998325aef https://github.com/ubuntu/yaru/commit/a0ff34f379d2b2d4673f4910970fdb02756b03b3 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to chromium-browser in Ubuntu. https://bugs.launchpad.net/bugs/1800260 Title: [snap] with CSD and Yaru, background color of the header bar is incorrect Status in chromium-browser package in Ubuntu: Confirmed Bug description: Description: Ubuntu 18.04.1 LTS Release: 18.04 Channel: Stable Version: 70.0.3538.67 Updated: 10/19/2018 License: Free Developer: Canonical Source: Snap Store Installed Size: 148.2 MB Settings -> Appearance: "Use system title bar and borders" was turned off. Close, minimize, maximize buttons became oval (more of stretched down) instead of circle. Turned back it on, buttons went back to normal shape (circle). It's a repeatable action. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/chromium-browser/+bug/1800260/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp