A related story, shortly after upgrading to the new iPHone. I noticed while driving I got a big album art preview on the Lock Screen while I was driving. However, after customising my Lock Screen it’s gone back to the small activity preview. I have tried a few changes to back, but no dice. New versions of iOS have been successively making the album art smaller and smaller, and i thought this was a return to form, but I guess it must’ve been a bug.

Just press on the small album art, then it’s big again.

I can't decide which is worse, undiscoverable software or software that always changes its behavior from what you just learned.

I believe the bookmarks panel just defaults to half-height now. You can pull it up to fill the screen, but otherwise — tapping the button opens it at half-height for me.

It’s resizable by dragging the top of the drawer.

You tapped the button that looks like a book, I'm guessing? It's full height in the "address bar at the top" design.