AWS WAF block url was lacked

Question

I'm using AWS WAF to block matched URL = "/login"

My context:

• example.com (not block)
• example.com/login (block)

Model: Internet -> ALB (with WAF) -> Web service (EC2) (nginx)

When the user accessed the login page directly (https://example.com/login) -> the request was blocked. WAF worked!

But when the user accessed the main page https://example.com and after that, they go https://example.com/login, the request was not blocked

Press ctrl + F5, page /login was blocked

What happens is going on and how to fix that? Thank!

This is my rule on WAF