You say that resetting the preferences does help?
What about just quitting and restarting? Or closing the document and opening it again?
That is a strange problem. I have not run into that. Does it help if you set your Pages panel to Horizontal instead of Vertical?
I’ve that happen here and there, but only when I have the “preview” turned on in the page panel preferences. When I turn that off, it seems to go away.
I keep that unchecked anyway, because I’ve found it slows down the scrolling.