Need help to connect bulb to router


I’m creating this thread as I’ve been trying for days to connect my Yeelight color bulb 1S (YLDP13YL) to the Yeelight app but it always fails.

I’ve searched every other thread about it and tried every solution with no success.

I’m located in France and using the Francfort server, phone is Oneplus 5T under Android 10.
MI ID: 6393714951

So far I’ve tried this with:

-changing router DNS to
-checked Wifi was set up to 2,4 GHz
-tried to generate a different wifi network creating a hotspot with another phone, still unable to connect the bulbs
-changed server to China

During the connection, when I have to choose the item to use with the app I can see the bulb (yeelink-light-color4_mibt9254).
When selecting it, I get a message “Successful connection” but from there it is like a loop when the window asking to choose the bulb network pops up again and again, asking to select the bulb network.

It seems that I can connect to the bulb wifi but the bulb can’t access the Internet, there is a “Connected, no internet” status.

Not sure but it seems that the issue is that I can’t connect to Xiaomi cloud.

Following my description, could you please help me and tell me what I can do to connect the bulbs to Yeelight app ?

Thanks a lot for your help !