Android JPG images not opening in Photoshop
I now understand that the problem lies in how Whatsapp saves JPG files, with a custom JPG format that is really a HEIC format.
If you change the extension from JPG to HEIC, even Photoshop will read the file.
I did a small Mac OS Automator app to change the file extension, that's useful if you have multiple "Whatsapp corrupted" JPG files.