A bit of an update... I was looking through my notes on anything I might have set special in Windows 10, and I came across something I set a couple of years ago. I had set the Control Panel \ Ease of Access \ Make the mouse easier to use \ Activate a window by hovering over it with a mouse . I like having that setting in place so that I don't have to click on a window to get it active.
Anyway, just for S & Gs, I unchecked that setting, rebooted, and then saved the layout for Opus once more.
So, here's the thing.. it sort of works now. It won't open two listers when I click the taskbar icon, but when I use the Settings menu and activate the saved lister, it now will open two listers, one on each display and maximized. So, we do have some progress here...
Leo, you said once we get to this point, we could possibly address what could be wrong with starting from the taskbar icon???
UPDATE: I tried something else just as a test. I changed Prefs so that Opus auto starts (delayed) with Windows, and uses that saved DualDisplay layout.
Rebooted, and there the two windows were, one on each monitor. They started maximized, which I would like to change to minimized, but they did start.
2 things... I still don't know why it won't work from the taskbar icon after windows has already started..
More important... how do I now get both windows to start minimized?? I don't see a setting for that one...