When a field is added to an object in Salesforce, you must refresh that object in Magentrix to see the new field in your portal.
To refresh an object in Magentrix:
Navigate to the Setup Home page.
Navigate to Extend > Salesforce.
Select the object you want to refresh.
Click on the More Actions button and select Refresh.
Select the fields to import from Salesforce and then click Submit.
For more information, refer to the Help Document.