OK they have found the issue and i just tested a beta version of the app and it now works for me over LTE. So if you were having this problem stay tuned you will have a fix soon for it.

Kevin SG wrote Did you get in contact with TP-Link support recently? Support contacted me last night and sent me a debug version of the app which i installed and captured the log files and sent them...

I am still having the problem and just figured support gave up on trying to help me.

gongmeiyan wrote Do you have TP-Link Tether and Kasa APP on your iphone？I wish you can try if your TP-Link ID can login in by Tether and Kasa APP on LTE network. TP-Link Tether worked fine over LTE

Ok so the issue still exist the app has permission to use cellular data. I ran a trace route using WiFi and LTE and will attach the results. My tplink id is smejico_iii@hotmail.com. The trace routes...

TP-Admin wrote Thank you very much for your detail information. Did you send us an email through [EMAIL="support@tp-link.com"]support@tp-link.com[/EMAIL]? We have received a same feedback today. A...