My application is currently using both the legacy system with ‘widgetIds’ and the new system which uses ‘ownerScreenName’ and ‘slug’ to determine the List in question.
I am using the exact same procedure and configuration, however scrolling works perfectly with the legacy system and is completely dysfunctional (even when omitting ‘noscrollbar’ from the ‘chrome’ param.) Note that I am using my mouse’s scroll wheel to scroll. This is the intended behavior.
Simply click the ‘Community’ tab in the top right hand corner and the Twitter timeline should embed immediately. I am logging the embed parameters to the console if it may help you guys.
P.S. The Twitter dev docs are overflowing for me in Chrome on 1920*1280. This has been the case for several weeks.