I have just purchased a AX1500 mesh system with 3 Deco X10 units

Changed my ISP for a 500 mbps internet speed increase up from 100, but i cant get pass  250mb max speed on wifi when connected to the wifi network created.

Mostly its around 160 - 200 mbps

When i connect directly to the modem via ethernet cable i get the full 500 mbps speed.

The main Deco is connected with the same cable as i used for the test.

Ive tried a single Deco, the speed improved slightly when i switched the 2.5g network off, its the same on my phone.

Have changed the cables a few times but the speed still the same.

Qos improved it slightly but not a lot.

Any advice on how to get better speed? or what to try

Thanks J