Hello There!

Last week I got my Internet abonnement upgraded to Fiber (1000/1000 Mbps).
Now I have a single modem with an Archer AX50. 
I tested my CAT ^6 cable in my modem, is does give me 900+ MBPS, so that's good :)

I plugged in my CAT 6 Cable from my modem to my Router (AX50) 
Now I wanted to test my Speed from my wireless connection, it should be at least 500+, I tried to test connection and it gave me only like 250 mbps.....

What did I do wrong? Which setting do I need to change in the router to get at least 500+ wiress spd, I tested btw on a Samsung Galaxy Book 360 so that is an newer kind of laptop...
plssssss helppppp :)

Btw I am an IT guy so u can talk a bit more technical to me if needed.