Why is my scalp itchy even after shampooing?

hello :)

recently I am worried because my scalp sometimes itches even after washing my hair. are you.

I definitely shampoo thoroughly and tend to rinse for a long time, but sometimes the crown or the back of my head feels itchy after drying it! 😢

At first, I thought maybe the shampoo wasn't rinsed thoroughly, but even when I make an extra effort to rinse longer, there are days when it's similar...

I'm not sure if my scalp is dry, if the shampoo ingredients don't agree with me, or if washing my hair too often is the problem.

For those of you who suffered from itchy scalps, did it improve after changing your shampoo?

Please let me know if using a mildly acidic shampoo or a shampoo specifically for the scalp would be helpful, or if I also need care like a scalp pack. 🙏