How to make "Ctrl-Shift" and "Ctrl-Shift-Arrows" shortcuts work together?

I am running KDE on Kubuntu 24, with default settings for almost everything. I am trying set up shortcuts to be Windows-like, as I am used to but I have gotten stuck on a weird bug. When I set Ctrl+Shift as the shortcut to change keyboard layouts, the Ctrl+ShiftLeft or Right combination (for selecting the whole word) stops working. If I set Alt+Shift as the keyboard layout change shortcut, the Alt+Shift+Tab combination (switch back to previous task) breaks. I have now set the shortcut to switch layouts to something weird and inconvenient so make the others work, but it feels like bug that must've been fixed by someone years ago. So the question is - is it really fixed? Or, at least, is there a workaround?