orders export custom field: shortcode not working

hi,

I use utmgrabber.com, and I see an extra field in my “woocommerce orders” (without using booster): “utm_source” (sourcepage of the customer).

However, when I use “booster orders export”, I do not see the option to select this field “utm_source”.

I have successfully added other “custom fields” to this export with a shortcode, and when I use [utm_source] (*) as extra “orders export field”, nothing shows 🙁
This shortcode is recommended by the utmgrabber, and works with other systems.

How can this be fixed please ?

Thank you

* (docs.utmgrabber.com/books/102-getting-started-for-handl-utm-grabber-v3/page/native-wp-shortcodes)