Octave Transposition issue on Windows 10

On Windows 10, when I press CTRL+ALT+UP (or DOWN) for octave transposition my screen is turned upside down, probably beacause of Windows 10 default shortcuts.
To avoid this conflict, I tried to change this specific shortcut in Dorico Preferences but it doesn’t work at all, no matter what combination of keys I choose, nothing happens…
The strange thing is that Dorico shows me this issue ONLY with octave transposition; If I change shortcuts for other functions, It will work!. What the hell…??

It’ll likely be your graphics driver stealing the shortcut. See Conflicting Windows shortcuts with Dorico's note input shortcut – Steinberg Support

As to customising the shortcuts, what is the specific name of the command you’re attempting to change? There are two different sets of shortcuts for octaves - one set determines the pitch direction of the next note, and the other alters the octave of the selected note(s). I suspect you’re muddling these up.

Thanks for your reply. Regarding the first link you gave me, I have to go more in depth: with Windows 10 It’s a little bit tricky remapping the shortcuts.
Concerning the command i’m trying to change, I’m using the italian version: It says “Su di un’ottava” e “Sotto di un’ottava” which mean “Octave up” and “Octave down” (Look at the attachment, at the moment of the screenshot there was no command for it) Dorico|690x387

Ok, you were totally right. I was muddling the commands. Actually there was another one for octave transposition. I found it. Thanks a lot!!