How to prevent the cursor from appearing when interacting with 3D Widget?

Hey!
The problem is simple to describe:
System cursor is normally not visible (and this is what I want), but it appears when, for example, I click buttons or hover over a text box.
When I click on “non-clickable” widget, then system mouse disappears.
I tried several things:

I want the system cursor to be always invisible.
Nothing I tried work, and I’m not really sure what to do now…

Video:

Thanks in advance for any help :slight_smile: