Salesforce Connection Bad Gateway Response in NWC Actions

I successfully created a Salesforce connection in my NWC environment. In a workflow, when I leverage a Salesforce action like, Create a Record, I have no problem connecting to the Salesforce account but the drop down fields (Stage, Office Responsibility etc.) from Salesforce that usually populate the list results now say Bad Gateway.

Every time I add a new field that leverages a drop down list the error message is Bad Gateway. 

Is this a Salesforce permission issue? (Screenshot attached) 

Let me know if anyone has run into this issue, or knows how to address is. Thanks!