MainStage: Problem changing I/O Bus labels

I need to change/reorganize the name of the I/O Bus in my MainStage.

I went in MainStage -> Settings -> I/O Label.

I see the list of Channel and Buses. And I can change each label. BUT:

1. I don't see the label of I/O Buses that I have set. I only see a "default" list like the next in picture:

My list is very simple:

But if I change for instance Bus 21:

I get:

On my view either there is a bug or I'm doing somethings wrong ....

Can anyone check if you are getting the same problem ?

Maybe I make a mistake: but how to make the change just replacing the old name "CLICK" with a null ( cancel it ) or rename it ?

Thanks Giuseppe.