Unable to set new shortcut keys in Lectora

I'm trying to change the paste function from Ctrl+v to F3, but can't seem to do it. I've done the File --> Preferences --> Hotkeys thing, and it shows up as F3 when I open Lectora, but still only works with Ctrl+v. I use the Dvorak-style keyboard, which makes the standard shortcut inconvenient to use. Thanks.