Mine is also much straighter. Part of the problem is genetics, part I believe is that the area is drying out faster than much of the rest of my head, also plopping on top of my head pulls it straight so I never do that. Roller jaw clamps help somewhat, both before and after diffusing to partially dry, also I cut an inch off my underlayer!
2a-2c, medium texture, porous/ colour treated. Three years CG, growing out mechanical and chemical damage = breakage and very high porosity. Past armpit length heading for waist.
Treatments: Komaza protein, Komaza Matani, coconut oil with sugar syrup. Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume
Styler: Umberto Giannini jelly, Boots curl creme, Rockin RInglets
Experimenting with: Mega-Tek, Curl Harmony reviver, Elvive Full Restore 5.