I know there has been a lot of talk about stuttering on the firestick. After a LONG time looking I think I finally found my solution. I’ll post what I did here in hopes to help others.
First I updated my router firmware. Making sure you have the latest firmware for your router will ensure it’s running at peek performance.
Also I made sure that both local and remote streaming were set to maximum make sure to hit the save button to save your change.
Next according to a tip found in this plex article: https://support.plex.tv/articles/203810286-what-media-formats-are-supported/?_ga=2.5072244.654504828.1576696909-1385293019.1575128313
I changed the maximum h264 level to 5.1
Just push yes on the notice that pops up… so far I have watched 3 videos with absolutely no stuttering!
Merry Christmas & Happy Plex Watching!