Unable to move the "Green Cross" for the preview

Greetings,
I’m having a problem that I can’t resolve.
I’ve searched online in every way but can’t find a solution.
I use Mac OSX with UE 5.2.1 (but also with a previous version) I cannot in any way move the green cross to see the animation preview when I create a “1D Blend Space” by mixing two different animations.
The animation works correctly, but even holding “hold control” I can’t do anything.
I also tried with other keys but nothing, it doesn’t move.

Anyone have this problem?
Thank you