[ride][preference] does it feel better for women on top to have less in/out or up/down (friction)? Or is it lack of 'form'/'knowhow'?

Hello! First post. 25m. Of the about 7 sexual partners I've had sex with, most don't do much up down, in out motion. It's more of a rock back and forth where there is not much friction. It doesn't do much for me stimulation wise, though I love seeing gf (21f) ride. I can't cum in this position due to the lack of stimulation. I can't tell how much she enjoys herself because she is still moaning but sometimes seems frustrated and will tell me to get on top or that we should do doggie. She doesn't really switch it up and move her body in a more up down friction movement.

Is this from her not knowing how to ride/feel comfortable leveraging a more friction based movement?

I wonder if it's to stimulate clit but she still does it sitting fully up where there doesn't seem to be clit stimulation.

Ladies, did you have to learn to ride a dick? Or did you do what felt best from day1? Any advice for coaching her on how to ride better?

Thanks!