@System77 -- I have Fibre gig, which has never surpassed 400 Mbps
If you have a fast desktop/notebook computer, you should get over 930 Mbps via an Ethernet cable.
If you are connecting via WiFi, the 400 is likely to be the maximum speed of your computer's WiFi adapter.
You need a WiFi adapter capable of "Wireless AC", to transfer much faster than any "Wireless N" adapter.
My usual speed testing devices are either a ThinkPad with Intel Dual Band Wireless-AC 8265 adaptor or Xbox Series X (Which is why I asked for the Wifi 6 modem)