How confident are you that you are getting all of the Solo switches? You video does not show the lowest layers. Is the Comp background set to purple or is that a purple Solid Layer or purple Shape Layer?
Try selecting all of the Layea (command + a, Mac; control + a, Win) and then click the Solo Switch for any layer. That should get everything.
All are top layers except #7.
Hello, new to the forum and I had the exact issue using the same set of files from the Udemy course. The solution I used for my mac was option-click. If you are using a Windows machine, it is alt-click. See the link.
I hope this helps.
This tutorial is heavy for begginers, therefore I am not following it at the moment. I found following tutorial from Udmey is good to learn basic.