How to control two dashboards separately?

I have two additional monitors, with two dashboards running.

I have the "show next dash screen" control set. The problem is it changes both dashboards at the same time.

How can I set controls for each dash separately?

Note: These are HDMI monitors, not USB or VOCORE, etc.

I should also note that in the dash settings page, the per device controls had a bunch of old "web" entries which I "forgot". It now has nothing in it, and doesn't seem to populate.