Edit: this was all stemming from some kind of issue with my child theme. It was still referencing Pro 6.2.5 despite changing the parent theme in style.css. Fiddling a bit sorted that out, and now it all works as expected.
One of the sites I am testing with the latest Beta doesn’t have the option for Scroll up within the Sticky section. On a fresh install the option is showing up.
It is also not visible in the Element Inspector
On an upgraded site:
Happy to share credentials if this is not replicable anywhere else easily.