Facebook released in app built in browser few months back that is aimed to open up the link you click from your facebook app within the same window. Though it might sound interesting, for few people it was not really a heart welcoming feature who would prefer their web browsers on openning a link. If you are one of those disappointed facebook lover, follow the steps below to disable in app facebook browser for external link and revert it back to its original state.
Instructions:
1.) Tap the three horizontal line menu button on top right.
2.) Click the App setting by scrolling down
3.) Locate and tap ” Always open links with external browser ” and you are done.

It should be all fine by now and do remeber to just double check just to be sure, by checing your Facebook timeline.