Editing functions (fade in/out) in grid disappear

What would cause me to lose the ability to edit fade out (dragging the corner) in an event in the grid. In the pic here my bottom purple track has the icon in the top right corner when I mouse over it but in the track on top it’s gone. I have done a lot of editing to the top track so it must be something I did. Cubase 10.5


Hi and welcome,

The upper Audio… is an Audio Part, not Audio Event. You cannot make a Fade Out on the Audio Part. Bounce it to Audio Event, then you can make Fades.

Bounce it ??
My question is : what action i did was leading me to this state ?