Hi Jason,
Thank you for getting in touch with us, we do appreciate your time.
Thank you for attaching your CSV file as it is of much help. I have taken a look and it appears that your custom Fields are currently not mapped correctly in the CSV as you would need to have the “Custom Field: …” column header in order for the Import to map the custom fields to the markers.
Please see our example of a CSV file with Custom Fields in it here: https://docs.google.com/spreadsheets/d/1Yzozn1D74OCq9i2-UY3Zd22rv_zRO8Xy/edit?usp=sharing&ouid=109776664046501539721&rtpof=true&sd=true
Please may you ensure that your CSV file follows the same structure and confirm if this helps?
I look forward to hearing back from you.
Kindest Regards,
Matthew