Usual shortcut for Copy, Paste, Delete, Undo, Redo cannot be safely used to interact with a focused TextInputControl: the system menu bar takes the event as well and calls the action associated so that there's a competition between the action at TextInputControl level and the menu bar one. It gives various stacks and potential infinite loops from which you cannot recover and have to kill SB.

Drop say a TextField on Content: thanks inline editing with Cmd-V a string in it, it's enough to bump the issue.
In Inspector it is the same problem with all textual properties. In hierarchy the inline editing is at risk all the same.