OK, thanks. It must be because the dots are on the “sfondo” layer. Click the white thumbnail (frame 1) in the sfondo column. Then erase the dots.
Also you can change the sfondo layer to red, so it shows exactly what’s in that layer. Click the gizmo with the little black line on it at the top of the sfondo column – and change to red. Right now both your layers are black, which is confusing, because you can’t tell them apart.
I hope this helps and solves the problem. Please let me know.