I upgraded to 4.21 (i have the same issue in 4.22) and i was making a small game for android, and i realize some textures were rendered black (from time to time or in a random way) I found it was the mipmap generation (or at least that’s what i suspect)
When i set mip Gen Settings to NoMipmaps in the texture/level of Detail settings all is render normally. But i don’t want to report it as a bug because could be my mobile the problem. I have a Samsung Note 4, so if somebody have time just make a simple scene with a cube, and a simple texture attached to base color, does it gives you render problems when you move around, does it turn black, does it solve setting mipmaps to none in the texture?. If so i will be sure is not a mobile specific problem and report it in the bug section. Thanks in advance
http://ruinzgames.com/images/Screenshot_texture02.jpg
Captures from my mobile. It was a particle test, here i discovered it render fine a some distance. Material has no alpha, just a simple texture to base color.
In any kind of preview works fin, it just fail in my mobile.