Playback buffering issues with certain files

[CedarM]

Server Version#: 1.25.8.5663
Player Version#: 1.42.1.2926-415b0e14

Newer Plex Annual pass user here. I’m having an issue that I’m having a hard time understanding. I have very jerky playback, and frequent pauses for buffering. It takes minutes to view a few seconds of playtime. While certain movie files won’t playback smoothly, most others work perfectly. I’m not sure I know what distinguishes them.

Facts:

• Server is a Raspberry Pi with library on an external USB drive
• Playback issues persist on ios client, mac desktop client, apple tv client, and chrome browser (mac) client)
• Downloading the movie (using the client download button) and the movie plays fine in the client. Movie file also plays fine in VLC player.
• There is plenty of local bandwidth on WIFI.

Any ideas would be appreciated!

Uploaded screenshots…
Pink Panther plays poorly. After Yang Plays as expected.

[ChuckPa]

Which RPi are you using ? ARMv7 or ARMv8 version?

May I see the DEBUG logs which captures one of these jerky playback sessions?

With DirectPlay, those are 99% either I/O or network config problems.
Given the drive is USB, I would expect it can provide the media fast enough so won’t consider it the problem.

How is the RPi connected?
Are jumbo frames in use?