@filou0726 Nope, you cannot. If the hardware version of the router is V4, you can only install the firmware for version 4, it's not allowed to install firmware other than that. You can check the note...

@raffael420 Hi, the WR850N is a customized version for the local market/ISP, it's suggested to contact the support where you get the device, or you can contact the local tech support to check if they...

@UnArchered You can install the beta firmware we provided in the above thread as per the hardware version of your AX20, then confirm if the connection will be built successfully.

@stratotp Thanks for updating on this topic. What's the model of your router? Is it also disconnecting the 5G signal, but the wired and 2.4G are pretty stable?

@PKP Are you using the same network topology as Akeneo's? You can describe yours in detail, and provide the static routing settings on your C6, we will confirm.

@ArnaudAl Try the following to verify if the issue lies in the VR300 or in the C4000: Login to the web interface page of the VR300, change it to modem router mode and build up a connection as you did...