From home, I play something. Then I press back on my remote to bring out the sidebar and the tab highlighted is Discover even though
Discover is the last item in my sidebar
I was on Home
My gracious understanding is that this is just a bug based on a wrong assumption. Though it wouldn’t surprise me if this was just another way for Plex to push Discover on to users.
I’m pretty sure you’re describing a bug that was introduced somewhere around 8.2x and was fixed in 8.28. But it seems like they used a different branch for the new demuxer/Discovery. It’s been reported before but we haven’t heard much from Plex.
Btw, It doesn’t necessarily go to the Discovery tab, it goes to the 6th tab, but if you have less than 6 items, it goes to the bottom, which is Discovery in your case.