Internet download speed drop by 50 Mbps after turn on 4 Yeelight bulb V2

I installed 4 Yeelight bulb yesterday and notice the internet speed drop on both lan and wifi.
So I try to turn off the physical switch and the internet recover back to normal speed

My connection is 500/100 Mbps fiber connection and when I turn on the physical switch to yeelight it drop to around 420-450 Mbps.

All my bulbs are on the latest version.

Could you please help me with this problem?