Custom TV_Shows Agent Thumbnails Not Displayed

Really confused by this because everything seems to be working perfectly.

In:
Plex Media Server/Metadata/TV Shows/…/Contents/com.plexapp.agents.myagent/seasons/X/episodes/Y.xml

the appears to be good, for example:

  <thumbs>
    <item external="True" url="https://i.ytimg.com/vi/DT37UwFPF8c/hqdefault.jpg" media="19c51373b75d8bc4ae9a5d3cca7ac526fc6a0500" sort_order="99"/>
  </thumbs>

The file:
Plex Media Server/Metadata/TV Shows/…/Contents/com.plexapp.agents.myagent/seasons/X/episodes/Y/thumbs/19c51373b75d8bc4ae9a5d3cca7ac526fc6a0500

exists and it is the desired thumbnail. But Plex does not use it for the episode. My code is:

						if episode_thumb:
							if episode_thumb not in episode.thumbs:
								try:
									episode_thumb_data = HTTP.Request(episode_thumb)
								except:
									Log('Update Failed to Retrieve Thumbnail')
								if episode_thumb_data:
									episode.thumbs[episode_thumb] = Proxy.Media(episode_thumb_data, sort_order=99)

What else am I missing?

Agent log doesn’t throw any errors, nor does the server log.

Did you ever solve this? I’m seeing the same thing.