I thought it would be a problem from the network but no, it might be a software defect.
My signal is always like this; two bars or three bars and i don't see problem with turning on mobile data, but then after turning off airplane mode and switching on the mobile data, it won't switch on as usual. Like waiting forever for it to happen.
I even switch to my other network to see if it's a signal problem (i own two different network), but still not switching on. I tried turning on the airplane mode again, and off, same with data. But still nothing happens.
And then after all the trial and error, i have decided to restart my phone. And guess what? After the long reboot, it is now on and so is the mobile data. I don't like the thought of doing this everytime if ever i turned on airplane mode again. Lol.
Anyone who experienced this before? If so feel free to share, so that i won't feel alone. Hahaha.