With same smartphone? Is there any interference souce nearby?

As wireless router of course tplink can connect to it. But for control I'm afraid you can only reach to it via Kasa

A mac address is mapped to one vendor but a vendor can have many mac addresses.

Voice commands supported by tplink are stiff, only contain one in the link: http://www.tp-link.com/en/faq-1356.html If not helps, you can try to change another name for Christmas tree and retry. Once...

Strange thing. You have better contact TP-Link for help.

I'm afraid not, an indoor device has large difference with outdoor ones.