[Jondar]

Artwork Beef doesn't add thumbnails from web services itself, they should be set from the scraper, as an image file next to the episode video file, or a URL specified in the episode NFO file. The options to generate thumbs in Artwork Beef sets each episode up so that Kodi generates the thumbnail, but Kodi won't do it right away.

The options to generate thumbs need the Kodi setting "Extract thumbnails and video information" enabled, which may be disabled by default on some platforms, and then you need to navigate to a list containing the episode in the video library window (MyVideoNav.xml) to get Kodi to generate the thumbnail.

Yes. That's what I thought.

After taking a break from getting it to work, I realised that the missing images were due to the "Extract thumbnails and video information" being disabled in my advancedsettings.xml file. D'oh!

Basically, what I did to get it to work the way I wanted it was actually turning off "Get thumbs from video file" in Artwork Beef, and leaving Kodi's thumbnail settings disabled.  That got it working for me.

Thanks for your help!

~Jondar