It might be helpful to have additional info on your current configuration. I assume you have the Fiber plugged into the 2.5 G
bps Wan/Lan Port?
Where are you seeing the speeds you cite, on the listing from the Network Map Users link speeds?
Are there any special requirements for running a 2.5 Gbps Fiber connection and you have no ISP modem inside your house involved in your configuration?
Do you have a Wi-Fi 802.11 ax enabled computer you could check? I see the iPhone 13 is ax compatible, but a computer may give more info. Still, the iPhone should be showing a link speed around 2402 Mbps when on a 5 GHz network.
I normally use just the default settings for the Router but I do need to turn on the IPv6 ability. If you have made any changes, you might tell us what those changes are.
Maximus Z790 Hero,
Intel i9-13900k
Intel BE200