I have added a second keyboard language layout (Persian) in Linux Mint 20.2 Cinnamon and in the keyboard setting I've set it to use shortcut win+space to change the layout.
It works fine when the selected layout is the primary (US English) and the shortcut changes the layout to secondary layout (Persian) but when I want to change from (Persian) to (English) it doesn't work and I have to use mouse and change it from the panel icon.
I've changed the shortcut to alt+shift but the problem still remains.