Board Game Arena

Hello all! This is my first time posting. I have a question about destination tickets. I recently played a game, and my opponent had 6 destination cards. However, at the end, only 4 were counted. Does anyone know why this would be? I took a screenshot but am not sure how to post it because it says it’s too large.

If only 4 of the destinations were counted, most likely two of the routes were not completed.