I have a small software utility that makes use of software renderer. Since this utility runs in background I make use of a system tray icon to open the window when it is closed. Everytime I reopen the window, it fails to render it's content but the content is there. It becomes partially rendered when I interact with the content. This was working correctly with 5.7 software renderer but it doesn't work correctly with 5.8 integrated software backend.
This bug only affects Windows. This doesn't happen on Mac OSX. I haven't tested on Linux though.