Prevent Null Values from Overwriting Data in HubSpot Integrations

Hi! I need help to prevent null values from overriding data when pushing to Hubspot. Basically I am importing the lead from Hubspot and Country is blank, then the country data is being adding by Hubspot workflows afterward, but then Clay gets to the end of the table and pushes the null values into Hubspot. So the country data is gone. Thanks!