@user91 Here's the user guide for C80. The latest FW release includes the new WDS dedicated menu, as well as WPA3 amd IGMPv3 - refer this thread's solution.

@dazcuenaga Yes, a reboot is needed to set this properly.

You're on the right path. They should be able to solve that.

@MartasCZR What do you mean by "its still the same" ? What's your Internet port negotiated speed right now ? (refer my first screenshot)

@kononenkoni It seems to me that there's only one more thing you could try, before declaring it as a FW problem. I presume you already have made a lot of configuring on the device, but that's a last...

@Robinson_Chera Regrading your original question it's worth to take a look at this thread.