SUMMARY When moving the mouse cursor over the menu bar entries of "File, Edit, Settings, Help" each one of these will strobe on and off rapidly. STEPS TO REPRODUCE 1. Move mouse cursor over any of the menu bar titles. OBSERVED RESULT Strobing flashing. EXPECTED RESULT To highlight only once, to stay highlit, and not unhighlight until the mouse cursor moves off the item. SOFTWARE/OS VERSIONS Operating System: SteamOS 3.4.11 KDE Plasma Version: 5.26.1 KDE Frameworks Version: 5.99.0 Qt Version: 5.15.6 ADDITIONAL INFORMATION No other KDE apps demonstrate this behaviour that I have noticed, only KCalc.
> ADDITIONAL INFORMATION > No other KDE apps demonstrate this behaviour that I have noticed, only KCalc. I have been able to reproduce the cause. Changing the font in the configure kcalc settings to a different font from the one originally selected stops the flashing. So, the issue is that the app takes issue (for some reason) to some fonts which are accepted by dolphin, kde system, etc.
Further update, it seems related to the width of the window. If it is made wider, the flashing in the menu bar will stop. KCalc re-sizes the window on re-launch. So the answer is that it is not making the window wide enough on launch for a given font.