Ethernet - Unidentified Network

Hello everyone.

First of all, thank you to everyone who takes the time to read my message.

I live in a house with 5 wall sockets for fiber.

I installed my fiber box and connected it to one of the fiber inputs that leads to the living room. There, the fiber perfectly reaches the internet decoder, which allows for a smooth WI-FI distribution.

I set up an office upstairs, as the WI-FI isn't very good, I would like to connect via cable to the fiber.

I therefore bought a switch router to distribute the entire connection to the different fiber inputs.

Here is the connection made as well as all the connections:

• Fiber box ->
  • 1 cable connected to the switch router for it to receive the connection.
• Switch router ->
  • 1 cable connected to the living room input, which works very well.
  • 1 cable connected to the Bedroom 3 input, where the lights are green and power seems to be coming through.
• Living Room Output ->
  • 1 cable going from the living room wall to the internet box, everything works very well, the WI-FI as well.
• Bedroom 3 Output ->
  • 1 cable going from the Bedroom 3 wall to the computer, Ethernet - No internet connection.

I looked on several forums, found commands to type via the Admin Terminal, nothing works, I've tried everything, netsh, reset, tracing, IPV4, IPV6.
I also already disabled/reactivated the network card.
I uninstalled/reinstalled the network card as well.
I bought a USB/RJ45 adapter to see if the problem came from my RJ45 port, it still doesn't work.

I tried to bring the computer down and connect it to the cable directly coming from the fiber box, it doesn't work.
The same goes for the cable that works well in the living room, it doesn't work on the computer.

I then tried with another computer, a Mac this time, still nothing works, in Bedroom 3, in the living room & directly on the fiber box.

So I don't have many solutions left.

What seems very strange to me is that the connection with the box works very well, the WI-FI works very well, but when I use the same cable, same connection, same input and output as the box, the connection doesn't go through, as if the connection doesn't accept any computer, Windows & Mac.

I'm open to any ideas.

Thanks again.

Have a great day.