Interesting. I wonder if "Auto" selected channel 149 if it would be 80 or 40. What test tool are you using?

use the Tether App although it is very limited. Also use your mobile browser and go to tplinkwifi.net

Look up "double NAT" to see how to avoid.

It could be your device is the limiting factor. See the below link on info on router settings although it is by Apple it is a nice source of info that applies to all router settings....

Unless you have multiple IP address from your ISP and a modem that supports it (most cases requires some type of a business account from your ISP) you cannot as you have only one IP address. What are...

Antennas are by nature frequency specific. For example a short wave or CB radio you tune the antenna by cutting it to a specific length. Many TV antennas have different length arms to get many...