Need advice for my hair before i result to drastic measures

I am 19, and I have only been taking care of my wavy hair properly for about a year now. It was a little rocky at first but now I've got it down good and my hair is a lot healthier and better at naturally waving without product.

My issue is, most of my whole head get waves just fine. They're a little looser in some places and little tighter in others. However, a section of my hair spanning the nape of my neck underneath all my other hair does not get wavy AT ALL even when using product. Im just confused and want to know what to do about it. I realized I had wavy hair because my hair would get really frizzy when I brushed it. This almost pin straight section of my hair doesnt get frizzy though so I dont know what to do.

I have layers in my hair so my layers get wavy and shrink up leaving this long straight section of hair running down my back so its pretty obvious.

I am considering cutting it really short since its under all my other hair and just trying to treat the new growth better. But if you have any other tips please share them!!!

My hair details are:

Dyed

Layered

Medium

2b

Bottom of shoulder blade length (~15 inches)

I dont know the porosity but my hair feels dryish usually

My current full hair routine is as follows:

Wash roots with aussie wave shampoo

Condition ends with aussie wave conditioner

Scrunch in water and leave in conditioner mixture

Scrunch in Garnier fructis gel

Use a 100% cotton t-shirt to get excess water and product off

Scrunch in not your mother's curl talk level 2 mousse

Finish by air drying or diffusing on low heat