"Please help me!!" does not do anything to describe your problem.
1) If it works, then don't worry about it.
2) It is responding to the lack of traffic: Login to the config UI and navigate to Internet WAN and Advanced on the left pane. Select your WAN PPPoA connection and then select Settings. Ensure that "On Demand" is NOT checked.
If it is already unchecked, we can work on other solutions.
3) It sounds like it is struggling to receive an IP from the router's DHCP server, but I would need more info from you to confirm that. It is possible that your DHCP Client service is set to Manual, but I cannot be sure at this time.