my yeelight LED bulb (color) does not want to connect to a phone

Hello, I send message because I bought a lamp yeelight LED Buld (color). I installed the application (mi home) on my mobile phone, I put it back to the factory settings then I connected by putting the password of my wifi, then the application loads up to 30 % and stops without an error message. When I finish the configuration, there is no device in my room. PS: the wifi of the lamp disappears after the carving

1、Please check if the lamp appeared in your router’s DHCP list.
2、If yes, please try change your router’s DNS to and try again.