Autotask API version 1.6 and later require the use of an API tracking identifier. It's important that you update the user connected with Simplesat to be an API user as things will break.
If you haven't created an Autotask API user for Simplesat yet, you need to create one. Select Simplesat - Customer Feedback Management as the Integration vendor. Then, reauthenticate your Simplesat survey and contact integrations using the API user credentials that you just created.
Note: To find your Autotask Zone, look at the number after "ww" when you log in to your Autotask account. For example, ww2.autotask.net belongs to Zone 2.