Seriously had enough for this - SORRY!
below is my 2.4 wifi connection settings. yeelight is not in my DHCP list …
Region - Australia
May I ask which device you are using? It would be best if you also provide your Xiaomi ID.
xiomi ID is 6727414046
and using the iPhone to connect Yeelight cooler bulb
It says wifi - yeelink-light-color1_miap6282
Make sure you’re not using a VPN also make sure that your phone doesn’t switch wifi network on it’s own.