Created attachment 134493 [details] empty panel SUMMARY Can't set an application's sound volume if the application is not making sound at that time. STEPS TO REPRODUCE For instance, try to set the events sound level, chose "Event Sounds" slider in KMix. At the moment there are no events, so no event sounds. Click on the slider's button, it will show the current value, let's say 15. Try to adjust the sound level. OBSERVED RESULT At the moment of slider button moving, the KMix sliders panel switches to an empty panel, with some general settings buttons. EXPECTED RESULT Be able to move the slider to the desired value, ideally test an event sound. SOFTWARE/OS VERSIONS Operating System: Gentoo Linux KDE Plasma Version: 5.20.4 KDE Frameworks Version: 5.77.0 Qt Version: 5.15.1 Kernel Version: 5.7.0-sabayon OS Type: 64-bit Processors: 8 × Intel® Core™ i7 CPU 920 @ 2.67GHz Memory: 23,5 GiB of RAM Graphics Processor: GeForce GTX 1060 6GB/PCIe/SSE2 ADDITIONAL INFORMATION As it can't be set, until this bug is handled, is there an workaround, a config file to set the desired value there?