Plex Update or Roku Update, which is the culprit? Possibly fixed now.
So, for the last few weeks (3?) TV shows and Movies randomly stop playing and exiting, leaving no log info, nor bookmarks, meaning I have to FF and hunt where it left off (Last night while watching The Emoji Movie, when the smiley girl said "OK, Delete him", the show just stopped and ended, great comedic timing, but very annoying)
So I hopped onto the Internet, to search for a rhyme or reason to this issue, at first I thought maybe it was a plex update issue, but after reading up on some roku problems with the recent update to 7.7, I came across a post about a secret menu and that reinstalling the update has helped some, so I opened the secret menu, updated the software and then watched a TV show completely with no cut off issues, so maybe that has solved my problem. I am posting this, maybe it will help someone else.
Secret Menu on the Roku 3: Press HOME 5 times, FF 3 times, RW 2 times
PMS - Unraid 6.3.5 NAS (Intel I5-4590 Quad Core 3.30GHz, 32GB, 1Gb network, 33TB storage, headless) PMS docker Limetech version, +other software
PlexApp - On Android Phones, Roku 3, Roku 4, Roku Premiere+ and Vizio Smart 4K UHD TV