Weird situation with zsh-syntax-highlighting.zsh

Hello there!
This is my first post here.
It's fast.

I've installed Kali Linux 2022.4 with all tools
I've created a user called 'user'
Then, I created a user called 'user2'

The problem here is the next one.

The user called 'user' has a working zsh-syntax-highlighting.zsh, but
the user called 'user2' has a NON working zsh-syntax-highlighting.zsh.

If I get into root with sudo su, the zsh-syntax-highlighting.zsh works normally but not into the NON ROOT user.
I'd appreciate some help

Thank you btw