This sounds similar to the issue I have with the officla Plex Kodi plugin (reported as a reply to Recent Playback Error - Multiple Clients & Files)
Feb 14, 2020 13:22:25.624 [0x7fc3735e3700] ERROR - ClientProfileExtra: missing protocol parameter
Feb 14, 2020 13:22:25.624 [0x7fc3735e3700] WARN - ClientProfileExtra: ignoring directive: append-transcode-target-audio-codec(type=videoProfile&context=streaming&audioCodec=ac3)
Feb 14, 2020 13:22:25.624 [0x7fc3735e3700] ERROR - ClientProfileExtra: missing protocol parameter
Feb 14, 2020 13:22:25.625 [0x7fc3735e3700] WARN - ClientProfileExtra: ignoring directive: append-transcode-target-audio-codec(type=videoProfile&context=streaming&audioCodec=eac3)
Feb 14, 2020 13:22:25.625 [0x7fc3735e3700] ERROR - ClientProfileExtra: missing protocol parameter
Feb 14, 2020 13:22:25.625 [0x7fc3735e3700] WARN - ClientProfileExtra: ignoring directive: append-transcode-target-audio-codec(type=videoProfile&context=streaming&audioCodec=dca)
Feb 14, 2020 13:22:25.625 [0x7fc3735e3700] ERROR - ClientProfileExtra: missing protocol parameter
Feb 14, 2020 13:22:25.625 [0x7fc3735e3700] WARN - ClientProfileExtra: ignoring directive: append-transcode-target-codec(type=videoProfile&context=streaming&videoCodec=vp9)
Feb 14, 2020 13:22:25.625 [0x7fc3735e3700] WARN - TranscodeUniversalRequest: at least one profile extra directive could not be read
Feb 14, 2020 13:22:25.631 [0x7fc3735e3700] ERROR - Streaming Resource: Cannot make a decision because either the file is unplayable or the client provided bad data
