This series' first episode of the earliest season correctly shows on TMDb as having been broadcast in 1964, therefore I, too, don't understand why 1974 is showing on the series' TMDb overview page. I'll move this thread to the Support forum's Content Issues queue, in hopes that another mod will know the answer.

Incidentally, anytime you have questions/concerns about a content issue, please click on "Overview" on a movie's, show's, or cast/crew individual's overview page, then select the "Report" button from the drop-down list that'll appear, and leave us a message via it. That way the report will post directly on the Content Issues queue.

I think I have figured out what might be causing the issue; the first season for 1964 has the season number 1,964. The first season should have the season number 1. All of the seasons have their year as their season number, which is incorrect. I’ll ask Travis to fix them.