Probably on overwatch you make different movements, playstyle might differ from apex in many situations. You might use different scopes in different situations as well. Even if you got the same fov and sensitivity, that's one of the MANY reasons why it might feel different. Trying to match the fov is your best bet, if it still feels uncomfortable, just play and adjust it until it feels fine, without looking too much at the numbers. That's what I would do at least. We can adapt our muscle memory to learn new patterns, it's not like we are forced to have the same exact sensitivity for every game, i never had any problem with that and I always played FPS games at high level. But that's me, might be different for you.