I moved into a new house in October, I got the Archer V3 router as the ISP didn't provide one and that is in the middle of the house. from there to the outer walls is 6m either side of it, at the the furthest points the wifi signal was poor so I purchased 3 x Deco E4, I originally thught they would all connect together as one network but apparently they aren't compartble and it used to annoy me when I would come into the house and my phone would connect to the archer, but then when I go further away the speed would drop and I would have to manually conect to the deco network to get working wifi

to try and make this better I read online that the RE330's are mesh extenders and will extend the range of the archers network, so I bought 2 and am trying to set them up but it's not working.

firstly, the range is poor, I am trying to get one of them 4metres away from the archer with only a concrete block wall (100mm thick) between it and it's telling me that it's too far away

secondly, the RE330 is broadcasting a different SSID than the archer, it's TP-Link_XXXX, I thought that it was supposed to be the same network?

thirdly, i can't connect to it, my phone just says wrong password. If i look in the Tether app it tells me that "its in a onemesh network and will sync the main routers network settings". so if that were true why doesn't it let me connect to it using the same password as the archer?  in the tether app it actualy shows my password of the RE330 as ?undefined?, so i tried to connect to the RE330's network with that password and it works...

but it's a different network name and I am still no better off.

these things are just working like range extenders with different networks? what am i doing wrong?