Webform Select not Mapping to CM Multi Field

I have a custom field in CM that is a multi-value field. I have created a Webform field with type of select and has multiple values with multiple options available (non-listbox) using checkboxes.

I've mapped the field to my new CM field, in the Webform CampaignMonitor field UI and when I submit the form, the milti-field values in CM do not get carried across at all, not even one value as the parent issue indicated was happening before.

I applied the patch from the parent issue and still no luck (yes, cleared all cached after patch).