This article describes an issue with Pardot form submissions in Episerver DXC environment. The underlying error message is the following:
Either the user and/or API keys are incorrect, or the API key has expired.
For more information on this error and other Pardot errors please see here.
By default Pardot expires the API key every 60 minutes. For more information please see here.
Episerver handles acquiring the API key so the customer does not need to be concerned with that Pardot design choice.
This is a product issue resolved in EPiServer.MarketingAutomationIntegration.Pardot 3.0.1
Please update the nuget package to resolve this issue.