ionFullApp Walkthrough page

I purchased the ionFullApp template from ionic market and created an app using this template.
There is a walkthrough page which has a login button, that redirects to the login page where a user can enter their email and password.

When testing the app on iOS and android, there were no issues and no errors. However, after the app has been released, I get this problem where the login button on the walkthrough page that is meant to redirect to the login page does not respond. There is no click, and the page does not redirect.

Does anyone have any idea why this might be happening?

The line of code for the login button on walkthrough page:

<a class="login button button-block button-stable" ui-sref="auth.login">
          Log In
        </a>

ionic v1, latest cordova version.

Did you ask the person that sold you this template?

They don’t respond fast enough. There are questions posted over 2 months ago with no response from them.
https://market.ionic.io/starters/ion-full-app