After updating to Chrome v61, scrolling capture looks like it is going to work, but then the resulting capture is incorrect.
Update 9/19/2017: To fix this problem, please install the latest update to Snagit 13.1.4. To install the update, open Snagit and browse to the file menu Help > Check for updates. Or, download the update using this link.
As a workaround, please use the Custom Scroll capture method.