This is a small visual bug.

When choosing multiple Processes (using the Ctrl key) and clicking on the Value Display processes, only the last one clicked will be highlighted (blue border).

The copy/past function works fine and copies all selected objects, including the multiple Value Display processes.

To illustrate (see pic below): the tree processes on the left (Context-Free.3 and 2 Value Displays) are selected with Ctrl + click, but only Context-Free.3 + the lower Value Display are highlighted. The result of a copy/paste operation can be seen on the right (all 3 objects were successfully copied)