I have a similar "problem" with my hair. In fact, I've kept it short most my adult life to try and not have to worry about it. I Canmore easily straighten it the shorter it is.
I have large S curls with smaller ringlet (think shirly temple) on the lowest nape of my neck. The other hair actually gets curlier the longer it is because the curl has more room to develop. As it gets longer, the hair has a chance to move how it wants. KWIM? I'm a 2c---3a.
Rae ~ 2c/3a ~
"The Longer the Hair, the Bigger the Blob."
Porous, very dense but fine hair. Medium everything else.
Wife to a 3c Curly Guy
Mom to a straight and a curly.
CoWash: Trader Joes TTT
RO: SM Gold label condish
Home Made FSG, followed by SM Smoothie, Plop, then AG Curl trigger, and diffuse. Finish with SM Hold and Shine spray.
Always wash upside down.