Android app not working in some cell phones

I made an app with vuforia and Unity, it has several targets for different characters, in my cell everything works perfectly, but in some cell phones when I look at the target the character does not appear and the screen starts to flash, what could be this problem? For example, my wife owns a Samsung J4 that runs the targets that have videos, but the targets with characters occurs the same, the screen starts flashing and the character does not appear