There is no exif information in any of your images.
This is what I get from your images when I check the file contents
file IMG_3371.jpeg
IMG_3371.jpeg: JPEG image data, JFIF standard 1.01, resolution (DPI), density 96x96, segment length 16, comment: "CREATOR: gd-jpeg v1.0 (using IJG JPEG v62), quality = 85", baseline, precision 8, 1000x750, components 3
And this is what on a image from my own phone for example.
file IMG_20180725_132436.jpg
IMG_20180725_132436.jpg: JPEG image data, Exif standard: [TIFF image data, little-endian, direntries=13, datetime=2018:07:25 13:24:36, GPS-Data, model=Pixel, resolutionunit=2, height=4048, yresolution=196, orientation=upper-left, software=HDR+ 1.0.163413028z, xresolution=224, manufacturer=Google, width=3036], baseline, precision 8, 3036x4048, components 3
The png images you uploaded are fine though. It's like the images are converting from raw to jpg incorrectly as the palette is only a single colour of black.