ionic app cannot connect cors enabled server with $http

cordova-plugin-whitelist seems to be "mandatory" at present.

install it :

cordova plugin add cordova-plugin-whitelist

configure config.xml

You can keep your current setup with * or change for more restrictive rules

add a html policy on index.html, you shall add a Policy also. To authorise everything, here it is :

 <meta http-equiv="Content-Security-Policy" content="default-src *;
 style-src 'self' 'unsafe-inline'; script-src 'self' 'unsafe-inline'
 'unsafe-eval'"