User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0

Steps to reproduce:

When switching from any desktop to the one where the Firefox window is present,
only the window managers window title and borders are shown. The window content isn't drawn (shows the background image of the desktop).

To trigger a redraw, something as simple as moving the mouse pointer over
the window is enough.

Actual results:

The Firefox window content is not drawn (the desktop background is visible)

Expected results:

Virtual Desktop switching should show the Firefox browser window content without the requirement to force a redraw first.

Tested Firefox version: stable (68.0.1) and nightly (Jul 31. 2019). Also tested before with older Firefox versions
Tested graphics cards: Radeon X280 (radeonsi and amdgpu kernel driver) and X580 (amdgpu kernel driver)
Tested Mesa (radeonsi) versions: 19.0.8, 19.1.2 and same behaviour with 18.x versions before
Desktop environment: XFCE 4.12 / Xorg 1.20.5

WebRender enforced with MOZ_WEBRENDER=1. Without WebRender the window content is always visible
after switching Desktops. No other GUI application shows this behaviour.

Other than this glitch, WebRender appears to be fully working with those AMD graphics cards and drivers.

I've updated Xorg, Mesa versions and even graphics hardware over the past year and this behaviour
was always present when enabling WebRender.

Can you still reproduce this bug if you run Firefox with additional MOZ_GTK_TITLEBAR_DECORATION=none environment variable?

Is it possible to get a screenshot of this to share?

I've attached a screenshot that shows the error state.

MOZ_GTK_TITLEBAR_DECORATION=none did not help

There are multiple bugs with similar appearance.

1. Please remove Firefox-related environment variables.
2. Open about:config, search for "webrender", set webrender prefs back to their defaults.
3. Set gfx.webrender.force-disabled to true and layers.acceleration.force-enabled to true.
4. Restart Firefox.

Are you able to reproduce the bug with this configuration?

Oops, I did not want to dupe yet. But it's likely a duplicate of that bug.

Yes, this seems very similar to bug 1514148. I'll continue monitoring that bug.

About disabling WebRender. Of course the issue goes away by having it disabled.
The point was enabling it to test it with current AMD hardware and drivers so it
can be enabled in the future.