Setting password policy in OU

Hi,

I'm a newbie in AD DS and I'm trying to lower the password complexity requirements for users in a specific OU in the domain, but it's not working. I've created a GPO for that OU "MyOU" and linked it. Here is the configuration:

Load Policy: "Minimum password length" is grayed out and set to 7.

Default Domain Controller Policy (Enforced=False): "Minimum password length" = Not Defined

Default Domain Policy (Enforced=False): "Minimum password length" = 7

MyOU: "Minimum password length" = 5 And "Security Filtering": Authenticated Users

But when setting a password of a user in the OU, the "Minimum password length = 7" policy  is enforced. Users of the OU are members of the "Domain Users" group.

I know that child GPO objects take precedence (so OU should take precendence over Default Domain), but it does not seem to be the case here. i've tried "gpupdate /force", but still not working. What am I doing wrong?

Many thanks!