Your Wi-Fi router is a dual band one? If not, it is not necessary to buy T4UH which is a dual band Wi-Fi adapter.

By the way, what's your expected Wi-Fi range?

Place the wireless client and WA854RE next to each other to ensure a more stable connection between them. WA854RE can only be upgraded wirelessly...

The link in the thread you mentioned is for TL-WR841HP V1. But your model is TL-WR1043ND V1?

Your internet service provider checked the line for you? When the telephone line is plugged into the router or your phone ONLY, is it working properly?

Update: Out of curiosity, I tried my brother's iPad Mini version 8.1.2(12B440) but no problem at all. :)Maybe you should update your iPad Mini. Anyway, if there is any update on your side, pls report...