Created attachment 115837 [details] a difference showing the panel before and after disabling compositing w/out any changes in open applications SUMMARY The panels graphically freeze whenever compositing is turned off. No exceptions, all widgets don't update their look, including the window list plasmoids. It still works as behaved, except the graphical freezing makes it near impossible to identify where everything is. This does not apply to pop-outs like launchers and the color picker plasmoid. Also, the panel doesn't just freeze, it reverts to a seemingly arbitrary state. STEPS TO REPRODUCE 1. Disable compositing by pressing Alt-Shift-F12 or launching an application that disables it. 2. The panel reverts to an arbitrary state and freezes graphically. OBSERVED RESULT Panel reverts to a seemingly arbitrary state. EXPECTED RESULT Panel has graphical effects disabled but everything still works. SOFTWARE VERSIONS (available in About System) KDE Plasma Version: 5.14.0 KDE Frameworks Version: 5.50.0 Qt Version: 5.11.2 ADDITIONAL INFORMATION The graphics card is a Nvidia GT1030 with propietary drivers at version 390.87-10.1.
Confirmed, disabling compositing causes panels to no longer update. SOFTWARE VERSIONS Arch Linux KDE Plasma Version: 5.14.2 KDE Frameworks Version: 5.51 Qt Version: 5.11.2 Nvidia 410.66 on GTX 980
*** This bug has been marked as a duplicate of bug 353983 ***