Before my phone was said to be rooted by root checkers, I tried many rooting apps, both Android and PC based.
The first significant change which happened occurred when I first installed and used the app called 360Root. 360Root seemed to install an outdated su binary in my system. After that, Root Validator tells me "Root Denied", rather than the usual "Root Unavailable". I tried to update su binary in SuperSU by chainfire, but the installation failed again. After multiple attempts to update the binary,
I thought I should try a PC program called KingoRoot. I used it after downloading and installing it. Kingoroot ran and completed successfully, but checking it in Root Validator still says "Root Denied". I tried again, and it still said sucesss. This time, some, but not all apps that require root like Busybox recognized my device as rooted, so I am able to install BusyBox applets. Kingo Superuser disabled SuperSU, although SuperSU still didn't work that time because su binary is just not updated.
Then I've tried again KingRoot, which succeeded in taking over the root from Kingo. I checked the root status in Root Validator. It now looks like a good news to me, because it tells me "Root is available". However, after opening some root required apps, they still don't recognize my device as rooted.
So finally, I had tried to replace KingUser with SuperSU by downloading terminal emulator first and then the "how-to-replace-kinguser-with-supersu.zip" file. I've followed the instructions perfectly, and it did replace it after updating the su binary and making SuperSU a system app. All the root checkers say that my phone is fully rooted. But, the apps that require root are still saying that I don't have root. Until then, I've noticed that there is a fifth line in Root Validator which says, "SELinux is enforcing". I downloaded a SELinux mode changer which can change SELinux modes from enforcing to permissive and vice versa. Even after changing that and rebooting, the apps still did not work. What could be the possible solution for apps not recognizing that I am rooted? Am I officially rooted? Is this condition have something to do with KitKat's improved security?
TL;DR: Root apps succeeded, and root checkers all say that I am rooted. However, apps that need root are denied root. SuperSU is installed.