I just found a couple of comments on Side-by-Side viewing that appear to have been blown off by people that don't understand the need for the Feature.... However, I do recall doing it in the past, so I would think it should be considered a BUG since it did exist years ago.

I haven't needed to have two PDFs open and synced in a while, so I was very shocked to find that I could not do this anymore. Seriously considered digging out one of my really old versions and converting the PDFs back to that version.

So to the head of the Development Team... Just because your coders don't get it, that's not a reason to blow off a VERY USEFUL feature. And no, the built in Compare will not work for me (or the other comments I read). I actually think the Compare feature is a waste of time, but I'd never suggest getting rid of it because I'm sure there are others that use it frequently for little word changes.

Acrobat Pro 2020 users (So please don't add this for those that use the web. That will never happen with any of my client's PDFs.)