Sis, liking something, or not liking something doesn't have anything to do with your gender or gender perception. If you decide you're not feeling painting your nails that's how you roll. If someone tells you that you aren't fem enough because your nails aren't done, I hope you turn around and tell them that they can have an opinion about your nails when they are paying for the polish.
I'm not trans, but I am a cis-woman/lesbian. When I was a teenager I was always told I wansn't gay enough because I wasn't listening to Melissa Ethridge, or dressing a certain way. Those same people weren't buying my music or my clothes, and their opinions mean even less to me as an adult.
We grow over time. Our likes and interests can change, and that is just life. (Although I get for you that the nail painting thing was a way you felt connected to your gender, but as you have grown, you have likely found lots of additional things that make you feel connected to your gender.)
If you are a woman, you are a woman, cis/trans doesn't matter. You should be a woman in the ways that make you happy. If that means no nail polish, then you are a woman that's not interested in nail polish. You're as much a woman in a dress and heels as you are in slacks and flats. Live your truth, and tell the haters that they can have an opinion when they are in a position to finance your life.
Good luck sis.