Custom Key Assignment with Letters

[satpalsharma]

Custom Key assignment such as 'Command + F" (toggle full screen in PLEX) or just "I" (Info box in PLEX) doesn't work. Or for that matter any assignment with a Letter in it. If I select other keys such as Enter, Escape, Backspace.. etc. they all seems to work fine but If i try to assign a Letter it won't work.

Is this is a known issue? or is there any workaround for this?

[satpalsharma]

When I use small letters and not CAPS i.e. 'i' instead of 'I' and 'Command+f' instead of 'Command+F', it is working like a charm.