So I got it to work by going into the Add-ons information for that app and clicking on "Run". That forced it to run again, and this time it imported the watched status from the trakt.tv account. Obviously had to do that on both of my Kodi platforms.
It did have a few problems however with episode specials. I manually enter many specials. These specials are not part of thetvdb.com. I create an nfo file for each one. Trakt doesn't recognize these since they aren't in any online database. I didn't know what it would do with these but now I have my answer. If the item isn't in its master database then it's ignored.
I also do something not conventional when I manually enter some of these specials. For specials that are related to a specific episode, e.g. a previously on, or making of, I use the same season and episode number as the episode itself. For example the filename of the pilot for Expanse looks like "The Expanse s01e01.mkv". I added a deleted scenes for it which has a filename of "The Expanse s01e01 (~Deleted Scenes).mkv" and there is a matching nfo file that has a very short text in it:
<episodedetails>
<title>Dulcinea: Deleted Scenes</title>
<season>1</season>
<episode>1</episode>
<aired>2015-12-08</aired>
</episodedetails>
The tilde in the filename tells my code to auto generate the nfo file.
Yes, I know this "breaks" the rules. I do it this way because the normal convention of doing something like "The Expanse s00e123 (Deleted Scenes).mkv" using season 0 for specials looks awful to me when it's listed in kodi, and it avoids me having to dream up a unique episode number. I tried this once years ago to see what kodi would do and it behaves exactly as I would want. If I watch the episode it marks it as watched, but not the special even though it has the same season and episode number. Kodi is smart enough to track these separately.
Well this now turns into trouble when used with trakt. It sees both as the main episode and doesn't see the difference between the episode and the special because it uses it's own database to decide what is what. The result? When you watch either the episode or the special (with the same season/episode number) it will mark the episode as watched on the trakt account. Then when it imports that watched status back to the other kodi platform it will mark one of the two files as watched and for me it's typically marking the special regardless of which was actually watched.
Yes, in hindsight I should have know better, but it did give the desired effect I was looking for until I tried to use trakt.
This is of course my own fault for not adhering to the convention so I can't whine too much about it. I probably have close to a 1000 specials entered this way. I might write some code to automate renaming the files and fixing the nfo files for them at the same time. I'll need to think about how I'm going to come up with unique episode numbers for them.
Oh well...
