did you create individual configuration?

make sure the rule priority is at the top. then check conflicting rules if any

If the bandwidth management rule you created for the custom application in your Sangfor IAM 5200 device is not capturing any traffic, there are a few steps you can take to further investigate the issue:

Verify the Configuration: Double-check the configuration of your custom application and the associated bandwidth management rule. Ensure that you have correctly specified the external server IP addresses and any relevant port numbers or protocols. Make sure there are no typographical errors or missing information in the configuration.

Check Traffic Logs: Check the traffic logs or monitoring logs on the Sangfor IAM 5200 device. Look for any entries related to the custom application or the IP addresses you specified. Verify if there are any matching traffic entries for the custom application rule. If there are no entries, it indicates that the traffic is not being classified correctly.

Review Traffic Classification Rules: The Sangfor IAM 5200 device uses traffic classification rules to identify and categorize network traffic. Ensure that you have appropriate traffic classification rules in place to correctly identify the traffic destined for your custom application. Verify that the IP addresses you specified in the rule match the traffic classification rules and that they are configured correctly.

Test Connectivity: Perform tests to verify connectivity between the Sangfor IAM 5200 device and the external server IP addresses. Check if the device can successfully establish connections to the IP addresses you specified. Ensure that there are no network issues or firewall restrictions preventing the device from reaching those IP addresses.

Seek Support: If you are unable to identify the issue or resolve it on your own, it is recommended to reach out to Sangfor support or consult their documentation for troubleshooting steps specific to your device model. They can provide further guidance and assistance in troubleshooting the issue.

• Check if the traffic is hitting the IAM device: Verify if the traffic from the external IP addresses is actually reaching the IAM device. You can use tools like tcpdump or Wireshark to capture the traffic and check if it is being forwarded to the IAM device.
• Verify the application configuration: Ensure that the custom application you have created is configured correctly. Check if the IP addresses and ports associated with the application are correct and that the application is enabled.
• Check the bandwidth management configuration: Verify that the bandwidth management rule you have created is set up correctly. Check if the rule is enabled and that the priority is set correctly.
• Check the firewall rules: Check if there are any firewall rules that are blocking the traffic to the custom application. Ensure that there are no conflicting rules that could be preventing the traffic from reaching the application.
• Check the NAT configuration: Verify that the NAT configuration is set up correctly and that the external IP addresses are correctly mapped to the internal IP addresses of the application server.
  
  

Do you only have 1 channel on your bandwidth channel?
If not, try to move your apps channel rule to the top and make sure the type is parent channel.