nissan altima trans problem?

hey all, so my brother just picked up a 2005 altima with the 2.5, auto, and about 80k. he’s had it for 2 weeks and just started to notice that when he’s going slow the trans shifts real hard from 1 to 2, only when youre going like 15 or less though. i checked the fluid and what not everything looks/smells fine. anyone have any ideas what could be causing this? like is this just gonna be like an easy filter/fluid swap, or a headache in the making? thanks for any help

there is a soleniod pack in those trans. that control shifts…i bet its that…I had the same issue on one of my old maximas…it either wont shift or shifts uber rough…where did he buy it from??? The pack it pretty pricy…I opted to buy a junkyard trans and never had an issue form there on…

I would still try a fluid filter change before anything though.