Nighthawk RAX45 speedtest only shows half the available bandwidth

[vhep]

I just purchased a new Nighthawk AX6 router and have 1gbps up/down fiber connection. When I run a speed test directly on my computer, I get the full 1 Gbps but when I set up the router, and do a speedtest on the router (in the built in software) I only get about 500Mbps. No Qos or Traffic Meter. Any suggestions?

[plemans]

Don't use the built in speedtest to check speeds?

It rarely saturates gigabit because it chooses the closest server and not the fastests server. And there's no way to choose which server it uses. many speedtest sites struggle to saturate gigabit. 

I have gigabit and the speedtest hasn't once maxed out my connection. Only through testing a hardwired pc and trying different speedtest servers or my ISP's server do I max it out.