Offline Forzathon and Multiplayer

Since the update of August I can not play multiplayer and forzathon is offline.
It also does not work on Forza Horizon 3 (neither multi nor forzathon).
The Xbox Live app is ok.
The network tests are ok.
Internet connection: Connected
Xbox Live service: it is operational
NAT type: Open Server
connectivity: Connected
Latency: 32ms
Loss of packets: 0%
Windows antivirus ok and firewall activate and ok.
But impossible to play in multi.
Thank you in advance for your help.

The concern comes from the livebox.
Because when I connect the PC in 4G on my phone it works.
By cons I can not find where.