The slow connection band
What the quiet band at the top and the loading pill mean.
When your connection stays slow or drops for a few seconds, a quiet band appears at the top of the page. It goes away on its own when the connection recovers. When a page change takes a moment, the page you are on dims slightly and a small loading pill shows until the next page arrives.
Inside a Toolbox tool, the decisions pill hides with the top bar unless something is urgent, and a new notification shows the bar for a moment.
In Decks, Export is under Home, Export and opens in its own window (a picture of a slide, handouts, notes pages); PowerPoint and PDF stay under More. In Pages, File, Download opens a list of file types.
This appears where your workspace has the new organization tools switched on. Where they are off, everything works as it did before and these screens do not show.