A couple of TV Show naming issues - Plex won't add these

It is of utmost importance to not only have the file names and folder structure correct, but to also take great care of where your tv show library is pointing at.
taking @tom80H 's example from above, your library should be pointed at the (tv show folder) and nowhere else. Not above this folder and not below.

(tv show folder) <--- library points here
-- Dr. Oakley, Yukon Vet (2014)
-- -- Season 05
-- -- -- Dr. Oakley, Yukon Vet (2014) - S05E04.mkv or
-- -- -- Dr. Oakley, Yukon Vet (2014) - S05E04 - Bear Trapped.mkv or

If you have experimented with different namings before, you must perform the Plex Dance.

Filebot is a great software, but you need to tell it that you are using Plex and not Kodi.
The tv show format string for Filebot with Plex is like this (a little bit extended from the default, so it cares automatically for sidecar subtitles and ‘special’ episodes):

D:/Series/{n} ({y})/{episode.special ? 'Specials' : 'Season '+s.pad(2)}/{n} ({y}) - {episode.special ? 's00e'+special.pad(2) : s00e00} - {t.replaceAll(/[`´‘’ʻ]/, /'/).replaceAll(/[!?.]+$/).replacePart(', Part $1')}{'.'+lang}

You might want to replace the first part of the string (D:/Series/ in my example) and put there the exact location of the ‘tv show’ folder on your system.