My suggestion would be to duplicate the problematic item first. Then remove the components one at a time using the content editor (start doing this with components that are not included in the working pages).
You can do this by going to:
Presentation tab => Details => Final Layout => Controls => Edit *(select component to remove and save)*
Then go again to the experience editor to see if the problem occurs. If it does remove another, and another etc.
Alternatively, what sometimes helps is to create a new Empty Layout. Which is essentially a stripped-down Cshtml view, with just basic HTML and top-level placeholders (maybe add minimal js assets like jquery, etc).
Then set that layout for the duplicated item. That should hopefully restore the EE controls.
Then start looking in the console to see if any errors and again start removing components till you find the culprit.