We're getting reports of switching of mobile data failing on some phones because the manufacturer/carrier probably decided that an additional permission is needed to do that (which we can't get because it's a system permission), but unfortunately that doesn't happen on any phones we have here, so I suspect it's a modification done by local carriers. I'll check if we could get some of them.
LeviXIII, could you please check with the newest version (1.2.1057) - edit two profiles so one would turn mobile data on (Internet Always ON) and the other would turn it off (Internet Always OFF), and try to switch between them in Manual mode and see if it does anything with Mobile data? Also do you know any other app that somehow switches mobile data on/off and actually works on your phone?
Thanks,
Ondra