Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
The issue should not be with the data connection or the 1000 values being returned. These should all be fine unless the 1000 values are incredibly massive in size. If you believe there is an issue here, modify the data connection so that it returns 2 very small values (like the values "1" and "2"). If it persists, that is not your issue.
From the error message, you might try looking into the rules inspector and evaluating whether you have any circular rules (i.e. A updates B, B updates A... or A updates B, B updates C, and C updates A). These would cause such an error.