Cubase 8.5 Problem with Key Editor!

Hallo everybody,
I have little problem with Key Editor.
When I click on note and I want to move, it disapears. Here a screenshot. Ist very difficult to work with that. Did anybody else had a problem like this? Thank you for your help! :unamused:

Hi and welcome,

There is a drag-and-drop transparency setup in Preferences. Check this settings, please.