I was trying to use the shortcuts "Edit with Medlodyne" (Ctrl M) and "Remove Melodyne" (Ctrl Alt M) in Studio One 126.96.36.199495 Win x64. However, only the "Edit with Melodyne" was working. Then, after going to the Keyboard Shortcuts tab in Options, I realised that Ctrl + Alt + [any key] doesn't work at all for any key combination! It is just ignored as a possible shortcut. Studio One does recognize Crl and Alt separatedly (both to program shortcuts and as a command in the editors) but not when pressed together (Ctrl + Alt + [any key]) and since to remove Melodyne you need to press Ctrl + Alt + M (as the standard shortcut) it just doesn't work. Funny enough I was able to work around it by re-programing the "Remove Melodyne" shortcut as "Ctrl Alt Shift M". I added a SHIFT and it then works. Very weird bug. Thanks God I am using a Stream Deck to program this shortcuts as shortcuts like Ctrl + Alt + Shift + [key] goes into the ninja region (to press and remember).
I wonder if anyone else had this problem and if Presonus is aware of this bug.