Freebox Revolution Issues

Hello,
After scouring forums for hours looking for a solution to my problem, I'm cracking and starting a new topic.
First of all, a few clarifications:

1) I am a newbie, so highly technical advice will be of no use to me unless it is supported by simple steps or links to clear tutorials.

2) I received the Freebox Revolution almost 2 months ago, and until yesterday everything was working perfectly (internet, wifi, phone, Freebox TV, Freemi Upnp server).

3) I have already performed numerous reboots (soft and hard), tried pairing the server and the player via Ethernet cable without success, and checked the connection with the remote control.

4) Each access to the Freebox server results in a 502 error.

So my problem is this: I turn on my Freebox player, I get to the Free menu, the Freebox TV menu is grayed out. I reboot: nothing changes. I reboot the server, nothing happens either.
After trying various manipulations, I realize that, in the disk menu, I no longer have access to the Freemi UpnP server, and then after going out and back into this menu, I soon have no access to the local disk of the Freebox player (disk unavailable).
My internet connection works, the wifi does too, but after pairing via Ethernet between the server and the player, the player remains stuck on authentication.
Can you help me?