I have a AX6600.  I live in a tiny condo.  The router is upstairs.  The AX6600 replaced a Nighthawk.  It is sitting on a little shelf away from the walls and ceiling.  I can barely get a signal downstairs.  The garage, which is 20 feet away, is impossible.  My connectivity is sporadic.  I had the Spectrum tech out and my internet is flying.  I tried a mesh system and that was a waste of money.  How can I get this thing to reach more than a few feet?