Hi Tom,
Is your form a browser form? If so, it might be because your form has code and it was published using the sandbox. There is an issue with sandbox forms not impersonating user accounts. The workaround is to admin deploy the form. This is slightly more work than Sandbox but it is required for any form that connects to data connections.
Please feel free to email our Support alias if this is related to DBXL or qRules.
Thanks for your patience,