Backstage change

What have we done with the Backstage operation? 10.17.01.58. I've always had a short list (6) of worksets. For me workset is a client. So when I switch from one client to another I simply select it under Recent WorkSets. One revision back we added "Configuration with Examples and Custom categories". Useless for me, serves no function.

Issue is if I change workset, open one file, close, Backstage shows the previous workset (a couple times it just exited [crash] with no error message). Guessing this has something to do with Pinned function, whatever that is. Seems I now must select the next workset, pin it, then it stays active and I get a split list of Recent Worksets.

Makes no sense to me, perhaps someone can explain the thinking/logic of this functionality and how I can Get Rid Of It!