Star Trek Episode With Mandela Effect & Disappearing Persons

Star Trek – The Next Generation

Parallels – After Worf returns from a bat’leth tournament, he is the only person who notices subtle changes on the Enterprise.

Worf essentially discovers the M.E. and no-one believes him.

Remember Me – Following an anomaly in a warp bubble experiment, Dr. Crusher finds that crew members are beginning to disappear, while she is the only one who seems to notice.

All Good Things – The final episode of TNG.
Q (a.k.a the quantum overseer) puts humanity to the test. Picard is shifted through time to different periods and has to convince his crew that he is indeed shifting and that the fate of humanity depends on him figuring out what is going on.

I love ST:TNG because of it’s ability to deal with concepts such as what we discuss in Retconned.
These 3 episodes are much more poignant after experiencing the M.E