Now how about you tell us which versions of Android these work on?
Since Android 6.1.x you can only change the DNS for tethered devices and nothing else. Everything else is ignored, no matter what you set or which app you use.
DNS + DNSCrypt...
1. my screen brightness is set to auto but whenever i am on call, the screen brightness is set to maximum.... how to stop that?
2. sometimes the screen is a bit pale (white is shown as yellowish or off-white) but after a reboot, it is fixed