Hi Russell,
This is a known issue with loading default values into a question that is not relevant on load, applies to parent layer or repeats. In this case the default value is stored in that question and sent to the feature service. In your case, because the default values are inside the repeat it is creating the first repeat record to be able to populate it.
There is a currently a open support bug BUG-000097105 in our backlog for this issue but unfortunately it did not get fixed for 3.5.
Have you tried setting the repeat appearance to minimal, which should avoid the first record being created automatically?
Phil.