@terziyski thanks for your reply, this the first time knowing about this CGNAT, ISP level issue. Is there any work around method, for now, I still can't connect through openvpn.

Hi, I just purchased a new AC1600 VDSL/ADSL Modem router, and run into this issue. I have setup a DDNS domain from NoIP provider, using the recommanded link from the web management. After setting up...