Getting Connection request error: connect ENETUNREACH error

Hi, We have built a new ACS Server, the CPE devices are getting authenticated and showing online on the server. But on the server, any changes done on the CPE device and tried to commit getting Connection request error: connect ENETUNREACH error. The server is assigned Public IP and the CPE is configured on PPPoE. How to make communication between them successful in this scenario.

Thanks and Hoping for some great responses to solve this problem.
Thank you again.

What happens if you make a curl request to the ConnectionRequestURL of the CPE from the server?

curl -i "{YourConnectionRequestURL}" -u '{YourConnectionRequestUsername}:{YourConnectionRequestPassword}' --digest

Do you see an error on the console after filling in the proper values for the command above and running it?

I’m not getting ping of the CPE device since it’s on PPPoe, server not learning any IP and it shows on the server pinging Pinging Error!.
I’m completely a fresher in this. A detailed answer would be much appriciated.

This doesn’t make sense. We use PPPoE and can ping all of our devices.

Does VLANs have anything to do with CPE to get to show up on the server or for server to ping their local IP’s? As server is on public IP whereas CPE’s are on local IP’s.

Screenshot 2022-09-29 174431
I have just attached screenshot for reference.