Adding Splash Page

I add a splash page to my website as index.html and change the main WordPress page to index2.php and everything works fine with the splash page and entering the website. However, when you click on any page contained within the WordPress it redirects to the splash page. The links are still valid and still are the same links that were always there, but they ALL go back to that splash page.

I’ve taken it down for now, so people can still use our website, but this is weird. Called our server guy and he said off the top of his head he couldn’t figure it out and would have to research it and ask some others, so I thought I’d come to the source.

Any help is appreciated.