I just installed a new yeelight RGBW LED bulb, linked it to domoticz and blocked via firewall any connection to internet for that bulb... so far so good

My problem is that I prefer "warm white" (with a yellowish hue) and that by default the bulb seems to gets automatically back to a "cold white" (with a more blueish hue) after a while. I don't know why

(i followed the wiki guide and managed to create a White temperature control dimmer = it worked but I had the same problem with my "warm white" light turning back to "cold white" after a while)
Is there a way to lock my light to "warm white" forever ? Without any extra control, just a switch ON = "warm white" ?
Thanks for any help
PS: I notice that Yeelight android app does not work anymore since my light bulb is firewalled = why would the app need internet when domoticz can control the same bulb without ? Is that android app - even if i can't use it - interfering with domoticz and putting back my bulb to "cold white" ?