The keyboard short-cuts for Copy (Ctrl+C) and Paste (Ctrl+V) may not work if the "Editor/debugger key bindings" preference is set to "Emacs" instead of "Windows". This may be worth checking for your MATLAB.
In order to check the MATLAB Keyboard preferences File -- > Preferences --> Keyboard --> Shortcuts. If the "Active Settings" option is set to "Emacs", the Copy (Ctrl+C) and Paste (Ctrl+V) features will be disabled. To enable these features, change the "Editor/debugger key bindings" option to "Windows" and click on the "Apply" button in the right bottom corner of the "Preferences" window.