How can I add or edit a wire stub on a library symbol?



E.G. I place a switcher in a block diagram, and want to add an input or an output. I can unlock the device and simply copy and paste a stub, rename it, and thats it. But this seems to be somewhat unreliable, as sometimes it does not lock to the wiring, or when the symbol is moved it does not move with it.



Any suggestion, please?

Thanks & Best Regards

Hanspeter Frick