Whenever I click anywhere in the document, the Structure View appears to be refreshed/redrawn (best I can describe the action). There is no smoot jump/scrolling. FM also appears to be refreshing/redrawing the Structure View three times. The same happens when using the scrollbar to scroll down the Structure View - it's not scrolling smoothly, but refreshing redrawing the text as it becomes visible. We had similar 'visual' issues in the past where document pages would only render when they become the active page - as though FM is only loading the content visible on screen into memory.
Try changing your Workspace to Blank and resetting it. Sometimes a visible pod/panel will slow things down.
@frameexpert I tried that and the same still happens. I've even tried resetting my FrameMaker Preferences by deleting the ..\appdata\roaming\adobe\framemaker\15 folder.
As a test, I opened the same document in FM2020 and the problem is worse - not only is the same thing happening with the Structure View pod, but the same thing is also happening with the document - each page is drawn as it becomes active.
I also tried another document - just to be sure it's not document specific - and got the same results.
What "extras" are you running in FrameMaker, or on your machine, for that matter?
What does Windows tell you is using memory and CPU when this is happening?
(Not to make you paranoid, but...) Have you run a malware check on your system lately?