Hello @Jerry-2565 , Thanks for reaching out to us!
The Device Provisioning Service throttles requests when the following quotas are exceeded. : Reference:
Quotas:
Each Azure subscription has default quota limits in place that could impact the scope of your IoT solution. The current limit on a per-subscription basis is 10 Device Provisioning Services per subscription.
- The following table lists the limits that apply to Azure IoT Hub Device Provisioning Service resources.
Note :
To increase the number of enrollments and registrations on your provisioning service, contact Microsoft Support.
Note :
Increasing the maximum number of CAs is not supported.