I have one Trakt account and two Kodi devices that have Trakt as addon installed. Both are registered at trakt.tv/activate.
When both of these Kodi devices are playing different episodes at the same time (me and my wife) only one is visible on the Trakt dashboard and will be set as watched when the episode is finisht.
Is it already possible that both episodes playing are set as watched and or seen by Trakt?
Thanks
Found this thread while looking for something else.
AFAIK the Trakt add-on scrobbles twice per item / episode. Once at the beginning to tell the Trakt website what your "currently watching", although I believe a delay can also be defined to prevent this action until a certain portion of the currently playing item has been actually played. Then again at the point where playback finishes (i.e: at the point the Trakt website changes the status from "currently playing:" to "Last Watched:") which occurs after rating selection (assuming you have that enabled).
Although I too have a Trakt account, and multiple activations (one for each of the 3 systems I'm able to run Kodi on), I've never been in a position whereby I've had multiple items playing on multiple systems concurrently, neither have I spent much time browsing their site to check. However, it's entirely possible that if they keep the "history" of watched items, while you may not see both on the dashboard per-se, it will have saved the fact that you have watched said content, presumably. if both items finish at *exactly* the same time (highly unlikely) then this could cause an issue.
The safest option would be to make use of Kodi's built-in "Profiles" feature, and set up separate accounts for you and the missus on Trakt. That will remove any potential ambiguity, but will require additional work on your part, granted.