After updating to 100.8 it looks like there is now a view called MTKView added to the hierarchy above the MapView. Looks like something related to Metal rendering... anyway it seems that this new view is having the effect of masking or hiding any ancillary views you may have embedded in the MapView. In my case I have a scale bar and floor picker that weren't showing up. I was able to work around this by pulling those items out of the MapView in the XIB hierarchy and positioning them relative to the parent view instead.
Guess this isn't so much a question as just noting a change in functionality.