Form conditions not working properly

The condition I have in my form is Enable / Require Field: 

If Preferred Contact? IN NOT EQUAL TO "E-mail"

Require  Phone Number 

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When I try the from and choose email, I still able to submit the from without adding the phone number. 

How do I fix it.

Please review the from: https://form.jotform.com/53217028331143

Thanks,

I just tested your form, and it's working as expected, If is not equal to "Email" it requires the Phone Number:

So, this mean when it is equal to "Email", it will not require the phone number field:

Let us know if you need more help.