Well, this post did help me resolve the scrollbar issue, and also thankfully led me to learn Flex Views/development, which should probably be my default from now on, but after-the-fact, I remembered that I had enabled the “Overlay Scrollbars” Google Chrome experiment in chrome://flags, which hides scrollbars until the end user starts to scroll…
So I’ve been deluding myself for the past couple months, and the original rationale for making this post was user error.
Nonetheless, I appreciate the opportunity to learn. Apologies for my regrettably “typical end-user - blame-the-software” approach and thanks very much for the help.
(I’m primarily a Mac user and “hide scrollbars” is a system-wide setting on Macs, which I always enable out-of-the-box, so wanted the same experience on Chrome in Windows)