In beta 4.8.5, If a show has multiple unviewed episodes showing on the Progress screen and I mark the next episode to be viewed as watched, it works but it then leaves the View next button un-highlighted and un-selectable, so I cannot select View next to mark yet another episode as watched. I had to exit and re-enter the Progress screen to mark the next episode.
In the example below, I had just selected View next to mark episode S23E02 of Law & Order, but now View next is not available for me to mark the next episode as watched.