I’ve noticed when browsing Plex’s free streaming options, if I’ve gone to the second page or beyond and clicked a movie or show, clicking Back in the upper-left area resets me to the first page of the category in question.
I don’t think the free streaming options were available last time I used Plex, a few years ago. If you want to keep eyes on the streaming options, I would advise letting people keep their place. They’ve already disregarded the first page of options, so resetting the view will show them content they’ve already rejected — they might decide to reject all of them rather than clicking the arrow even once.
Just a suggestion, but I bet it makes the player more attractive to use. 
Server Version#: 1.21.2.3943
Player Version#: 1.27.1.1571-2fface66