Can you also test for the result if you reverse the order of the modifiers?
i.e.,
4. Ctrl-click the event and drag it elsewhere.
2. While dragging, additionally hold down alt/opt key
There is only the Size Tool which has a setting for “Disable Snap” but that has no effect in the Key Editor on notes.
This issue was brought to my attention by another Cubase user, I could merely reproduce it.
Strange that you get a different behaviour. Are you on version 12.0.52 on PC?