Billing Details fields

Hello,

so since flexible checkout fields doesn’t work anymore, I’ve tried this plugin, like it already way more then FCF. However, i’ve come to one issue. For the Billing Details fields. I’ve disabeled every field except Email Address, because we don’t need the other information. However, instead of the email field shown, there are two field, one is blank with no information. However in the chrome elements inspector, this is shown:

<input type="text" class="input-text " name="billing_first_name" id="billing_first_name" placeholder="" value="">

I’ve checked again, the field is deactivated in the plugin but still shown? How can I change this?

Thanks for your help