Editor disappears SOLVED

I have 2 monitors acting as a single desktop. I want to display the user manual for an instrument on one screen and C8 with the plug-in instrument editor open on another. This works fine. When I have a plug in (in this case GA4) running with the editor open, the editor disappears as soon as I click (change focus to…) on the user manual. If I then click on the C8 background, or tracks or whatever the editor re-appears. How can I keep the GA4 editor in view while I am scrolling (for example) through the user manual on the second screen, or vice versa.
I’ve tried a few of the preferences settings but nothing works.

Setting the plug-in to NOT always stay on top ( in the editor window there’s a small icon on the top right) allows the editor to stay in view when the focus goes off Cubase.