Salesforce is rolling out enhanced domains to improve functionality and comply with new regulations.
FinDock has done the required updates to make this work for Giving Pages.
However, if you have a custom integration with the FinDock API (or any other API that requires authentication with the Salesforce API), you may need to take action.
In sandboxes, your domain URL will automatically be changed from
mydomain.sandbox.salesforce.com. If you are authenticating
https://mydomain.my.salesforce.com/services/oauth2/token instead of
https://test.salesforce.com/services/oauth2/token, you need to update your endpoints to use the new domain.