Keyboard language changes only once by pressing "Right Alt + Right shift"!

I use Manjaro Kde and windows 10 simultaneously on different SSDs; I’d like to use the “Right Alt + Right shift” combination on both OSs, in windows 10 it’s OK but on Manjaro kde i can only use it once and after that, the language doesn’t change at all!
is there any graphical solution?
(note that I can still change the language by “Left Alt + Left shift” anytime and every time i want)