I bought a Samsung Galaxy S5 [G900H] and I installed custom rom from here to get rid of most unwanted applications and having a pure and de-bloated android on my smartphone.
After installing this rom it's working perfect except that when I install (root)firewall applications like DroidWall they do not work as expected and if I create an allow rule for an application, application could not be connected even when I set it to be allowed to use wireless/mobile data. But if select allow rule for all rooted applictaions it works fine but its useless this way.
I also tried to use unroot firewall but it is giving this error message "The VPN is not supported by your device."
I also checked blacklist/white list mode and mode is set to whitelist only.
Does any expert know what problem should be and is it required for me to install other roms to cross over this problem?
Now I restored my android to its official stock version (I had created a full backup before installing a new custom rom) and tested both DroidWall and AFWall+ and the problem still persists. Seems this problem is a bug coming from Samsungs TouchWiz.