I usually used my Xiaomi Mi A1 as a Wifi hotspot (using my own data) to cast youtube video to Google Chromcast which connected to my TV (Panasonic Viera TH-43E410K, not a Smart TV), it works fine. When the Xiaomi connected to an external Wifi router (turn off mobile data and use the Wifi data), it is connected good. However whenever I turn on my xiaomi as a wifi hotspot, it always turn off the (external) wifi, so I can never use my xiaomi to cast any video to my Tv. Can anyone help ?