This particular servo seems to be a hybrid: it reliably returns to the same “home” position when I tell it “myServo.write(90)”. Values more than +/- 5 either side of that send it rotating clockwise or counterclockwise. There is no value that makes it stop in its current position, only one to send it “home”.
The video here seems to suggest a value of around 107 would make it stop but that doesn’t work for me: