Server Version#: 1.25.6.5577
Player Version#: 8.31.0.31215 (6f5d4f5e)
Direct play is not working on some videos on Android app. Video is playing fine after downloading it and playing from Downloads section of the app. See logs from both scenarios attached.
The media bandwidth exceeds the limit set in your Android app or on the Plex server. Plex is transcoding the video to get under the limit.
Having a bandwidth limit on a mobile device is not necessarily a bad thing. The quality of a mobile connection will vary from location to location. You will experience buffering if both the Plex client and server are set to Maximum/Original quality and the connection is too slow to support such a stream. If that happens, try lowering the quality setting on the mobile device.
Plex Android App, in Settings → Quality
Auto Adjust Quality = off
Limit Cellular Data = off
Remote Streaming Quality: Default is 2 Mbps/720p. Set to Maximum for Plex to play media at original quality (unless limited by the Plex server).
Plex Media Server
Check Settings → Remote Access. Set Internet upload speed and Limit remote stream bitrate to appropriate levels.
03-11 12:49:19.796 i: [MediaDecisionEngine] Starting media decision for: Parks and Recreation - S5 E15 (part index 0)
...
03-11 12:49:19.825 i: [MediaDecisionEngine] Analyzing media: 1920x1080 4333kbps (Container: mkv, Video: hevc, Audio: aac)
03-11 12:49:19.826 i: [MediaDecisionEngine] Bitrate 4333 exceeds maximum allowed (2000)
03-11 12:49:19.826 i: [MediaDecisionEngine] Resolution 1080 exceeds maximum allowed (720)