AiCloud not working in Internet mode, but working Intranet

[rsonandroid]

I have a strange problem. I have a AC-66U and my AiCloud works very well (both on the PC and the android app) when I am accessing it via intranet, but the minute I try to connect to it from outside my LAN (via internet), it doesn't work. I checked and there is no port conflict, ports are set to default under setting (443 for web access, 8082 for streaming), but it just doesn't work. The webaccess page just doesn't open, and the the android app access says cannot connect to router.

I thought it could be a DDNS problem, but no - I am able to access the admin page from web access, but not the AiCloud. Tried both the official firmware and currently on Merlin 376.49_5 = both have the same issue.

Any suggestions?