Have you thought about the Sun

do I spend money sending it back to Amazon or just fetch a lump hammer to it You will waist your money send it back, hold it and hope there is a new FW in future. meanwhile use it as AP or use Bridge...

You are right it's in STATUS under channel but not in wireless settings to do the change Just as a test change your router to G and for sure once you reboot your extender will get the new Widht, and...

If your main router is set to N forget that one but I cannot see how you change it on the extender. just to let you know see photo

If no change in wireless settings mode by default is bgn mixed change it to bg mixed

Just bought a WA850RE, and in general I am quite pleased with it. Then i don't understand with the extender and root AP in the same room Not a good idea having them in same room you might be over...