I can confirm it on Ubuntu 18.04, Firefox 67.0.4, NVidia video drivers, with any theme.
Interestingly enough, the corners are shown correctly when I start Firefox from a Slack link. I tried to use the same command line used by Slack to launch a link (which is just: firefox https://....), but that doesn't do the trick. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to firefox in Ubuntu. https://bugs.launchpad.net/bugs/1828728 Title: White corners when CSD is enabled on Firefox Status in firefox package in Ubuntu: Confirmed Bug description: With CSD enabled, Firefox 66.0.4 displays white corners at the top- left and top-right of the window. Ubuntu version: 19.04 (fully updated) Version: Firefox 66.0.4 (64-bits) Desktop Environment: GNOME 3.32.1 (default) GTK theme: Yaru (default) GPU: Radeon RX 560 Series (POLARIS11, DRM 3.27.0, 5.0.0-13-generic, LLVM 8.0.0) Expected behavior: rounded corners without the white corners, following the current theme. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1828728/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

