Keyboard shortcut for Focus Dashboard

Hi,

When i want to change the keyboard shortcut for Focus Dashboard to none in File -> Options and then tab Keyboard, it doesn't save the change.
For other keyboard shortcuts after i press Ok i get the message "Changes will only be applied after an application restart" and when i go back in the options screen i can see that they have changed. But not for the shortcut Focus Dashboard. I get no message that the changes will be applied.. and when i go back in the options afterwards it has changed back to its old value.

Kind Regards,

Pieter