Sorry i used the wrong words. I meant in 'inspect' view. The drop in fps is only in the 'inspect' view, whereas the fps&cpu goes back to normal in the other views, i.e 'watch' and 'profile' view
Now i'm aware of the drain, but it has gotten worse. I remember when i worked on my first project, and i used to get low fps, so i had to learn a lot and modify events and finally was able to get a stable 58-60 fps on my project in the 'inspect' view.
fast forward a couple of months, i also started encountering lag as op when i previewed another project i was working on.So i previewed my first project which i had gotten 58-60 fps before, and i find that it's not giving 35-40 fps in 'inspect' view. But like others in this post, goes back to the normal 60fps in the other views(As opposed to before where i got 60fps in all views).
I'm not techy so i'm not ready to point fingers, but i'm certain that something has changed somewhere to negatively affect C2.