I bought it from Vietnam and bring it to India, So first time i tried with JIO Sim and yes that was working but the firmware was not supported 464XLAT so it was not working in all devices so i turned it off and remove my sim and putted it to my iPhone, there 5g working fine no problem but yesterday i again putted my jio sim to nx200 and it was automatically switched to 4g+ but when itried to make it 5G Only mode, i see no network is showing and nothing, i restarted it but not work so i called customer care and asked why 5G network is not showing they said that you putted your sim to 4G handset so 5G network was disconnected, we again requesting 5G network to your sim and after 5min restart your phone. and yes after 5 minute 5G network showes. Then I again put to nx200 and again same problem as before. I dont know why its happening 

Please Help