Postnatal new hair knotty

[Chipsahoy]

Hi all.
After baby number three my hair fell out in clumps. Two years on and lots of regrowth. The growth under my hair coming from the back of my neck is all frizzy and curly and the rest of my hair is a mixture of wave and straight.
This new hair is about three inches long and constantly knotted. I don’t know what to do with it.
I use the garnier hair food and never use straighteners on this part of my hair. It’s miserable, it just doesn’t ever stay knot free. Not sure what to do with it. Do I need to go back to silicones? Lockdown willing, I have a hair appointment in two weeks so will see what she says.
Any ideas?

Hair changes with hormones.
Do you brush your hair daily? I ask because when i dont it gets so knotty.
I tried curly girl method, minimal bryshing, natural shampoo bars.... my hair didnt like it.

I brush my hair every morning and sometimes again if it’s very windy and become knotted. Even after a shower with a lot of conditioner it’s still badly knotted. My hair seems healthy otherwise. Not sure if this new part is or not

Never had this issue when I used “normal” shampoos. I don’t know if to go back. I used to use Aussie..