Problems with using Texture Quality and Texture Streaming on iPhone.

If you use the Texture Streaming option on your iPhone, Texture Quality will behave abnormally.
However, turning off the Texture Streaming Option works fine.

Normal only when Texture Quality is Full Res.
Half Res (1/2) looks like Quarter Res (1/4).
Eighth Res (1/8) looks like Sixty fourth Res (1/64).

Normal.
Half Res (1/2) when QualitySettings.masterTextureLimit 1.
Quater Res (1/4) when QualitySettings.masterTextureLimit 2.
Eighth Res (1/8) when QualitySettings.masterTextureLimit 3.

Abnormal (less than iPhone + Texture Streaming + Texture Quality Half Res).
Looks like Quater Res (1/4) when QualitySettings.masterTextureLimit 1.
Looks like Sixteenth Res (1/16) when QualitySettings.masterTextureLimit 2.
Looks like Sixty fourth Res (1/64) when QualitySettings.masterTextureLimit 3.

It seems to be calculated like this.

 int n = QualitySettings.masterTextureLimit;
 float normal_texture_resolution = 1/2^2;
 float abnormal_texture_resolution = 1/2^(n*2);

Tested on Unity 2019.2.18f1, Xcode 11.3.1, iPhone7.``