Nighthawk X6S makes wifi worse

Hi guys.

I didn't realize their tech support was for only 3 months. I set up the X6S AC3000 several months ago and it caused so many connection issues that I unplugged it and decided to deal with it later. Which turned out to be now.

Both the 5G and 2G connections work by far worse with the extender installed, across the board. Wifi connection often becomes so slow it drops altogether. Kind of sucks if it's in the middle of a Zoom call. It shows it's connected, but when I check the connection with the Wi-Fi Sweetspots app it clearly shows that connection is erratic and overall much worse than without the extender, especially in the spots we need it most (in between the router and the extender).

It shows "connected" on the status page, nothing looks out of order. I ran the setup multiple times, installed new firmware etc but overall it wrecks havoc on the wi-fi. It sits about 20 meters / 65 feet away from a Spectrum router, separated by 2 walls. I needed it to extend wi-fi to the roof (to which there's a direct line of site and around 20 feet) and it does a terrible job at it, although without it there's no connection over there at all. But at the extender location itself wi-fi works much better when the thing is unplugged. 

I was too busy with other things to deal with tech support at the time, but that thing is kind of expensive to discard as paperweight.

I noticed it shows "no connection" on the status page sometimes, even when connected. If i restart the Spectrum router it will show "connected". But works just as bad.