Mi Desk Lamp Connection Problem with iPhone7


I have Mi Desk Lamp and I cant connect my lamp to my iphone 7. I have download 2 different application some of which are Mi Home and Yeelight.

The steps are as below;

After install application (Mi Home) I selected the region China.
Then Add Device.
Confirm reset (After I pushed resset button, the lamp was blinking then for awhile lamp was shutting down. I pushed the open/close button to open lamp again).
next step is, go to wifi settings and selecting the yeelight. and connecting this.
after that I am turning back to app and the process is starting. At the end of percentage 100 the steps are going back to first step which is reset step.

For yeelight app,
Same as Mi home app just difference is; percentage is waiting 25% and then the app says connection fail.

Could you help me please?

Please refer to the link to see if you are the case:

Thank you [dingyichen]
The problem was about firmware uptade. That link solved my problem.