Tos is a huge offender. Like as stated before Turnabaout Intruder, women still aren't allowed to be starship captains, at least in the human world.
No explanation for it.
Another is "That Which Survives" where Sulu says "I don't want to have shoot a woman!"
Technically it sounds moral, but comes off really odd and sexist. Or pretty funny. As if it's more ok to shoot anything else,
Another is when someone does something horrible, and later the crew or captain lets the offender go and even helps them.
Another is where a bunch of mean aliens turn two crewmen into cubes, and then crushes one to powder (the female crewmen), and then restores the other, just to show their power.
Later Kirk escapes from them, calls a truce, gives them aid, calls them friend and sets course back for home without any mention of bringing the aliens up on charges.