Render :new form is blank

In my create method I have the following:

respond_to do |format|
if @purchase_agreement.save
format.html { redirect_to admin_purchase_agreements_path, notice: 'Purchase agreement was successfully created and is pending approval by the Loan Originator' }
format.json { render :show, status: :created, location: @purchase_agreement }
else
format.html { render :new }
format.json { render json: @purchase_agreement.errors, status: :unprocessable_entity }
end
end

I have these validations in my model:

validates :buyer_email, presence: true, if: :electronic_signature?

electronic_signature is a boolean. I am checking to see that if they want to use an electronic_signature that there is a buyer_email.

The problem I am having is that when there isn't a buyer_email and it fails the validation, it is rendering the form, however, the form is blank. When I debug it, I can see that my @purchase_agreement has all the original values set from when trying to save it, as do the params but nothing is displayed on the form.

I am at a loss as to where I have gone wrong.

Thanks