Accessing MinimServer Status

[Meffy]

Hello Simon. All of the sudden i encountered a little problem with accessing MinimServer Status on synology nas DS 412+ when i connect from ddns http://*****.synology.me and click on minimserver icon. I can access the web interface of minimserver if i connect on synology local ip but not when i connect from ddns. I have rinstalled a new firmware of my router (Asus RT-AC87U) and i even port forwarded minimserver 9790 but no luck. What im i doing wrong?
BTW it worked before router firmware update when connected to synology ddns.

I could appreciate any help.
Thanks in advance.
Regards Meffy!