maybe i was wrong.. F/20 & F/21

maybe i was wrong for saying that my girlfriend (21) is dismissive to me (female (20) whenever we have to part ways. for example, if im dropping her off at home she will leave without saying a word which will prompt me to say something first. to me that’s her being dismissive, especially when she argues that i could be the one to say it first and we’re in the car for minutes before she actually goes. i just expect her to say bye if she’s leaving, just like i do when i leave her apartment and she doesn’t say bye until i say something. she thinks im just complaining too much, and that if it was a problem why didn’t i say something before. it’s because it always feels like she spins it around to what im not doing. anyway, maybe i was wrong for saying she was dismissive.. but like, why did she get so defensive when i said she could say bye when leaving?