Shadows not showing

Hey guys,

Before that, I already asked the question related to shadows in AnswerHub but no answer. Please refer to that link to see the detailed question (and picture).

Anyway, I have tested modulated shadows and dynamic shadows from movable directional light towards any movable object, and both my Zenfone 4 and Galaxy Note 2 aren’t working, or not working nicely/incorrect. Not even using Unity 5, for addition.
However, I tried it on Asus Zenfone 2 (ZE551ML), and everything works just fine.

I’m starting to notice that both my Zenfone 4 and Galaxy Note 2 are Android 4.4.2 and using OpenGL ES 2.0, while the Zenfone 2 is on Android 5.0 with OpenGL ES 3.0 (it’s PowerVR G6430 GPU).

I’m starting to assume that it only works best on OpenGL ES 3.0 devices. If that is really the case, I don’t mind to drop any OpenGL ES 2.0 devices (and anything lower than Android 5.0, if that’s also the problem, but unlikely) for this issue.

What do you guys think?