When you create a conditional field and the paragraph that should appear/disappear based on a question, you naturally want to create the conditional field as follows:
If there is no Commission, the field will default to “Exclude this field”, which automatically inserts a blank placeholder in the document.
Instead of creating the conditional field as mentioned above, use the language below as part of your conditional field. Your conditional field should say:
if there is a Commission, insert the "Commission" and “Payment” paragraphs
if there is no Commission, insert the “Payment” paragraph
This way you don’t have an option to “exclude the fields” and you will have no empty placeholder in the document!