Soldato
I had a similar issue with really quite expensive ubiquiti gear (relatively speaking). Do check the 5ghz band. Mine was set to 40mhz but changing it to 80mhz got me to 400mbps.
This was a great tip, thank you @dlockers!
Bestest Top Tip, though:
Check internet speeds on a device that's actually capable of 900Mb...
...after my OnePlus 9 Pro went *crunch* the other day, it appears as if the internal 5G/WiFi antenna was damaged, meaning it could only connect to the 2.4 WiFi.
I discovered this when testing speeds on my son's £90 Xiaomi (600Mb) and my Doogee T30 Pro tablet (which got the full 900mb connection from anywhere in the house).
Panic averted and currently eyeing up Black Friday deals for a new phone.