Can't handle more than 2 devices or time out

Hi, I have 2 light bulb RGB and 1 ledstrip RGB , since almost a year now one light don’t respond, it’s not the same light each time , it’s random between these 3. Every time I asked if alexa or directly with the app to change the color or to turn on/off the lights one of them freeze and don’t respond, just unplug one and no more problems, the 2 device turn on/off and change color correctly on the first try but plug the last one in again and the problem come back. I wanted to add in the futur more Yeelight devices…but with this problem i don’t know if it is good idea, do anyone have a fix for this ? or at least the same issue as mine ?

My current server is EU but I tried every current server available
Account ID : 1861582362
I have reset the light a good 20 times now
I tried on a different router and same happened
plz help me