False CORS failure only in iOS mobile safari when uploading images

for laravel-5.4.* add following line in .htaccess file

Header set Access-Control-Allow-Origin "*"
Header set Access-Control-Allow-Headers "X-API-KEY, Origin, X-Requested-With, Content-Type, Accept,Authorization"

You're right, the CORS error message is very misleading. I've been struggling with the exact same issue for the past couple of days and it turned out the image I was trying to upload from my phone was too large for the app server I'm using which is nginx on Kubernetes; so the fix which works for me is to just add this annotation to the ingress configuration

nginx.ingress.kubernetes.io/proxy-body-size: "0"

to removes any restriction on upload size.