@Alexandre. the AP mode solved the issue, many thanks!

@Alexandre. yes I did this, see the result. So it is strange that When I put my laptop on the cable on the main deco (and switched off wifi on the laptop) I even not exceed 20 MB...

@Philbert I connect first with my laptop to the router of the ISP, then to the main Deco. both with Wifi I also witched off the 2.4 GHZ band, so only 5 Ghz is possibles did the same test on cable...

I directly connected the M9 plus to the router. I have a glass fiber connection of 200MB up and down. On the router the speeds is indeed 200MB up and down, both on the LAN cable as on Wifi. As soon...