using custompost to import, some custom fields don't show data

Hi.

I have tried to import many times and I do not success with importing CSV date to custom fields: coupon_start_date and coupon_end_date

Standard fields (title, content,…) are imported perfectly but the mention above custom fields do not appear.

Deal image (file_name) appear on back end when import image link, however, the image doesn’t show on front end.

My site: https://todayshowstealsanddeals.com/

https://www.ads-software.com/plugins/wp-ultimate-csv-importer/