PAC Display 10.2e Combo Box

I am using a combo box to list a set of test plans from a MariaDB table for the user to select.

I want to disable or hide the combo box when the test is started.

I do not see an attribute for visibility.

When I try to put a “blank” box over it, the combo box stays on top even though I bring the “blank” box to front.

In the strategy, I prevent the plan from being changed but it is easy for the user to be confused when he still has the option to select items from the combo box.

Am I missing any options?

You could put the selection box on a pop up window and have a button that opens it that you can hide when not needed.