Recently, I noticed I could no longer edit collection items on page through the editor. The haven't been any significant changes to my browser or site other than the following:
I thought this was due to a plugin I installed, called Loom for screencasting, which did not work while I was in the editor. I uninstalled it and tried a different browser as well and the problem persists, so it's possibly unrelated.
When I try to edit a collection element, on-page, the gray-lined box around the element freezes, and remains there even if I try to edit a separate element (most of the time, sometimes I just have to click outside the element).
Here's the read-only link:
Browsers: Chrome Version 58.0.3029.110 was where I noticed the issue. I then tried Safari 10.1.1