Hello  @AX11000 

Thank you for the inquiry. Wi-Fi range extender is mainly used to extend Wi-Fi signal to Wi-Fi dead spots, not to boost speed. 

OneMesh helps improve performance in wifi roaming when wireless device move between different AP, it's almost ' seamless' 

As RE receive signal from router and repeats the wifi signal, RE speed is slower than router's WiFI. 

You may start a thread in router subforum for slow speed and provide case details like the wifi link speed, which band, what device etc so moderator  there could help take a further look into that. Hope this helps. 

Btw, if router's wired speed is fine, you may connect a AP, or setup RE into AP mode to extend the network.