FileBot

This seems to be dependent on whether there is a tvshow.nfo file in the main TV folder.
If there is an existing TV show, and a new episode is copied to it using Filebot, Kodi will find it on a library update
If this is a new TV show, and Filebot creates the folder structure and copies the episode, quite often Kodi does not detect it.

If I try to force a rescan of the episode or season using Kodi, it finds nothing and says
DEBUG: VideoInfoScanner: Skipping dir 'D:\TV Shows\Top Gear\' due to no change

If I delete the tvshow.nfo and force a refresh of the series or episode, still nothing;
ERROR: VideoInfoScanner: Asked to lookup episode D:\TV Shows\Top Gear\Season 23\Top Gear - S23E02 - Episode 2.mkv online, but we have no episode guide. Check your tvshow.nfo and make sure the <episodeguide> tag is in place.

but if I force a refresh of the TV show, Kodi will ask to get the info from the internet and finally recognise the episode

Is this Kodi, Filebot or the new TVDB API?

The old episodeguide tag is very specific to the old TheTVDB API. FileBot is not generating it anymore and Kodi should not rely on it.

Best to repost in the Kodi forums. Newer versions of Kodi will eventually have to figure this one out. I don't know of any updates to the nfo spec yet though.

ok, thanks! If I disable the artwork switch in AMC, does that mean the tvshow.nfo is no longer generated, and Kodi will have to figure it out itself (hopefully working around this issue)?

Yep. That should work. Best to have Kodi do it's own thing if it gets confused by the nfo files.