ZoomIt gives black screen on dual screen Windows 10 Pro

Question

I have an issue with LiveZoom in a specific situation and hardware. Having an eye distrophy, I need LiveZoom (CTRL+4/CTRL+') to sometimes zoom in to have a closer view while working.

I just bought a new laptop (Acer ConceptD) with Windows 10 Pro. My second screen is an EIZO ColorEdge CS2730. I use it with "Duplicate screen" on. I downloaded Zoomit 4.5 from Sysinternals.

When I activate LiveZoom (to e.g. 125%) the laptop's screen just zooms in as expected. The second screen however becomes black This stays like that until I zoom out (Ctrl+Dn) to 100% and/or I deactivate LiveZoom.

I do not have this issue on 2 other laptops (HP Envy, DELL Latitude) with Windows 10 (resp. Home and Pro) and the same EIZO screen.

There is no issue with the Zoom alternative, but this is not a solution for what I need it for.

I tried swapping the LiveZoom shortcut key to CTRL+1 (Zoom), but this doesn't change the situation: Zoom (now CTRL+4) works well but LiveZoom (CTRL+1) gives the black second screen. So it is not a question of a reserved shortcut.

It is not the result of a "B"lack (nor "W"hite) key press: hitting "B" blackens both screens and does not undo this state.

I've been through all the Windows Updates (21H1/19043 1151). No software has been installed yet on this computer.

All laptops have a reduced, but compatible, resolution and a bigger text size and mouse pointer.

Can someone help solving this issue?

P.S.: What's the difference between zoomit64 and zoomit64a?