The problem is quite weird. If the switch option is not available in Windows GUI Interface, please try the method 2 included in the following article:
2 Options to Reset Windows 10 Microsoft Account...

Did it solve your problem or not?

Try to reset all the local security policy settings to default:

Open an elevated Command Prompt.
Run this command:
secedit /configure /cfg %windir%\inf\defltbase.inf /db defltbase.sdb...

I followed your tutorial and found out that the created account was not a guest account actually. It was a standard account which is a member of the Users group. A real guest account should belong to...

The settings of your account policies are correct. Are you using a Microsoft account (Windows live email address) for logging into Windows 10? Did you get the warning "meet password complexity...

Could you take the images of your password policy? Is your computer joined to a domain or not?
Please check out this article:
Change password policy settings - Windows Help
Make sure the policy...