Why am I transcoding?

Not sure why the profile levels are different, might need a sample of the file to check. There is nothing super wrong with that file. However:

coded_height=1088

That could be the cause. Chromecast can’t scale the video so PMS is likely transcoding to get this to 1080. Could also be that PMS is seeing the profile as 5.0. This is strange. Was this a new file or did you replace an older version? If the latter, it could be PMS didn’t update it’s info. Try a Plex Dance of the file.

Will need to logs from PMS after recreating the issue to dig further.