Unable to import null or empty values in Account Engagement

There is a Salesforce Connector setting to allow blank or null values in Salesforce 'win' over existing Account Engagement values. If you'd like to enable it,  you will need to open a ticket with Support for them to enable it for you. These are the two possible scenarios:

A. If your connector setting 'allow blank/null values in Salesforce 'win' over existing Account Engagement values' is enabled:
You should just be able to clear the values in Salesforce as long as Salesforce is the 'controller' for that field, or if the sync behavior is set to use the most recently updated record. Refer to How Sync Behavior Works for more information on this.

B. If your connector setting 'allow blank/null values in Salesforce 'win' over existing Account Engagement values' is not enabled and/or the prospect field is not mapped to a CRM field:
You can use an automation rule to clear the value.

For example, you could do an import, tag the prospects with 'delete [name of field] value', create an automation rule where Prospect tag :: is :: 'delete [name of field] value', and then add action to 'clear prospect field value' :: [name of field].

If you do not wish to enable the ‘allow blank/null values in Salesforce ‘win’ over existing Account Engagement values’ setting on the connector and your field is mapped to sync with Salesforce, you will need to temporarily pause your connector and manually clear the field value in both systems prior to resuming the sync between the systems.