This issue is mainly related to network environment and I don't think it is a bug. Maybe TP-LINK people can explain better and help you to further look into it....

How is it going now? My friend helped me to test by iPhone 6 and 6+ and we called each other but no problem at all. What's the MAC OS of your iPad Mini? Any other apple devices you can test in your...

I don't think it is a bug. There is misunderstanding... http://forum.tp-link.com/showthread.php?80417-Address-Reservation&p=158683&viewfull=1#post158683

There is a next button according to the emulator. You cannot see it? How many enties you add in total? Can you provide the screenshot as well?

When WA901ND works in repeater mode, the SSID will be the same as main router's SSID and it cannot be changed. WA850RE can meet your requirement because it allows us to customize the extender's SSID.

What's the operating system of your PC? All other options displayed on utility are grey out except the one you mentioned, right? Take Windows 7 as an example and try to enable WLAN Autoconfig....