TP-Link AC750 Wi-Fi Dual Band Range Extender

Had high hopes, but it did not work. Apparently the vendor just took something that was returned and shipped it back out without ever testing (as Amazon says they are required to do). The item I received had the previous owner's SSID (Gonzalez_home) configured. I reset the device to factory defauts and configured using the TP Link Tether app. This was to be placed between where my mother's router/wireless access point and the family room. The distance is not far at all, the problem is that between the family room and where the router/access point is located, there is a refrig in between, so this was placed in direct visibility of the router/access point (facing the West) and the Family room (facing North - it is in an L shape). Without the externder, I was getting 20M down (on a 300M circuit), with the externder, I was getting between 9 and 10M). If I go to the point that the extender is actually located, I was getting about 250M. I have owned a lot of TP Link equipment, and am getting ready to purchase some TP Link Omada switches and access points for my house to be able to have redundant ISPs (cable 1 Gig, 5G - 50Gig) due to work. So I am a fan of TP Link, but this vendor failed to test the hardware before shipping, and I got a faulty item - it has been returned.