Cannot come back to HCM page from a website using backbutton

Summary:

We have done a customization to have a link displayed on the benefits tile in self-service so that the employee can check the 401k plan details from teh website by clicking on the hyperlink,

Once the hyperlink is clicked, it takes employee to the website as expected but on clicking the back button, the HCM page (self-service page) is not back but we get an error message.