No connection to mysqueezebox.com from a duet

Dear squeezeboxers,
i've got a lot of difficulties to use my squeezebox server, duet, and so on ....
So i did a lot of things to find the issues. Here is where i stand now.

My installation is :
- LMS (version 7.7.6-112) running on a Synology211j (DSM 6.0.2-8451 Update 1).
- 3 squeezebox duet
- 4 squeezebox radio
- ethernet connection

As i had issues to connect all my devices, i removed them from my squeezebox account using (http://mysqueezebox.com/player/viewPlayers).

I changed recently my ISP (internet service provider) or FAI (in french as i'm french) : Livebox.

I gave a static IP address for my diskstation (hosting LMS) and two squeezebox duet (they were using dynamic address at the beginning without working better). The squeezebox radio have a dynamic address.



I opened the following ports :


I restore factory settings on all devices to register them again on mysqueezebox.com.
I didn't have any issue with my squeezebox radio. It works fine.

For the squeezeboxd duet, this is another story....
While i tried to configure one, i have this message :


When i look on diagnostics i have this :




i'm completely lost.
I cannot understand why it's working with squeezebox radios and not with duet....

i will appreciate a lot your help. do you see other things to do or to check ?

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