It’s very odd what shows (or doesn’t) in your screenshot. Here’s a screenshot of what I have when I open the file. Layers appear for me.
It could be that there is something corrupt in the file on your computer. You could try deleting it and downloading a new copy using the link in your sales receipt email.
If that doesn’t work, maybe you could try opening the file on another device and seeing if the layers appear.
If all else fails, layers are just a nice-to-have feature. You can always print the pattern with all sizes showing.
But it is odd that you don’t see layers but I do (and I’ve tested on different computers with different versions of Adobe Reader). Let me know if downloading a new copy or changing devices works for you.