@terziyski 

Thanks for the reply

I already tried different ports on the router with a laptop and different cables, so I think that the problem may be the firmware 

I'll update it and try again, will let you know if works

Thank you 

  @terziyski 

so I checked the firmware and it is updated to the latest version*
I tried again all the ports on the router with different CAT6 cables, but still capped at 100mbs 

here you can find a screenshot of the ethernet status on my PC

Seems that the speed (Velocità) is capped at 100 Mbps

here you can find a screenshot of the settings of the Ethernet controller port, where I selected "automatic negotiation"

I also tried to switch it to 2.5Gbps Full Duplex, but it is not working either 

Do you know what can I try to check to solve this issue?

Thanks 

  @terziyski 

I tried all the ethernet ports with different cables and PCs, but always the same issue 

at the end I returned the router and got a different model

after a 5 minutes setup here is the result 

At this point, I think that the issue was in the router 

Thank you very much for your help on this