Country and Mobile Redirect Professional edition plugin works for sites which are being cached by caching plugins such as WP Super Cache and W3 Total Cache etc.
Before activating the plugin, make sure you empty or delete existing cached pages, follow below steps:
W3 Total Cache:
Go to Performance Menu and click on the Page Cache sub menu. Look for “empty cache” button in W3 Total Cache page. Click on the “empty cache” button.
WP Super Cache:
Go to Settings Menu and click on the WP Super Cache sub menu. Look for “Delete Cache” button in WP Super Cache page. Click on the “Delete Cache” button.