Moviebase Will Not Retain History and Personal List Information for a Specific Show

I have an unusual problem with one particular TV show. This has been on-going, and I have tried hard to find a reason for it, but I’m stuck.

The show in question is:

“Not for Ourselves Alone: The Story of Elizabeth Cady Stanton & Susan B. Anthony (1999)”

It only has two episodes. I have marked both episodes watched and marked the show as watched and added the show to three of my personal lists. After I do this, the episodes show up in the History, the show is listed in the show History, and the show appears in my personal lists. Everything looks perfect.

But then after a short time, the show entry disappears from the History, and the show disappears from all of the personal lists to which I added it. The episode entries do remain in the episode History. This has happened over and over and over. I cannot make my entries stick for this one show. All the Trakt entries for it remain, There it is marked watched as it should be, and it shows as present in the three personal lists to which I added it.

I cannot come up with a cause for this, but I would really like to understand what is happening and get a fix.