Sprites not rendered properly on Android

I'm trying to run my game on an Android device (Moto X Pro/Nexus 6), and seems the 2d sprites are not rendered correctly. Once the game screen is updated, everything small sprite (using SpriteRenderer) went crazy like this:


The half-transparent hexagon sprites (blue and white ones) twisted and flew all over the place, while no problem with textured meshes (the gray ones with a stroke in the center). When there are particles in the scene, it goes even worse.

Everything works fine on my PC and Android emulator. Can any one help me? I've totally got no clue...

Thanks in advance.