Lamp disappears from devices list

Hello there.
I’ve got two Yeelight 1S bulbs, I have the same issue with both. when I try to set up the lamps, everything goes fine and they connect to the wifi and I can start controlling them and it finishes the process, then it just goes away from Yeelight’s application devices list and I can no longer control the lamp!
I’ve tried everything! all the servers, anything I could do. it just disappears right after the setup.
(plus, I tried setting up using Mi Home app, did not work! couldn’t find it in the Bluetooth search! but that’s not important. I’m just looking for a way to set up my lamp :((( )

I use iOS, yeelight app version: 3.3.36 (newest)
MI ID: 8154961088

I really wish you guys help me out, I’ve been waiting to get these lamps for a long time :((

Guys this is your iOS applications bug! I logged in from an android device, my both lamps were available in my devices lists and it works perfectly!!! Please oh please fix this :((((