How to fix: Samsung S4 locks after every phone call

[AC Question]

It's really annoying, is there any tweak to fix this? I want my s4 to stay unlocked when I dial/answer phone calls. I've read some articles on the net, and this is somewhat an annoying s4 bug. I hope someone can help me on this one.

PS: I already tried using "on end call", it dind't fixed my problem.

Thank you!