I can also get auto scroll to freeze fairly consistently on Windows 8.1.
If I just leave it for long enough, or click anywhere after more than a couple of seconds, it will freeze.
If I then click, Accordance goes dim.
I can usually fix it by minimizing Accordance and it's fixed when I maximise it.
I can actually see that the moment I click on the Accordance icon it is fixed (it goes non-dim).
I've tried this in a bunch of tools and texts.
also on 10.4.4.5777 (beta)
iPhone 6+ :: iOS 10.x || Windows 10 :: Samsung ATIV ultrabook i5 :: 1.80GHz || my wife controls my MacBookPro :: OSX 10.11
Accordance Demonstrator in Australia