Passportjs redirect adds hashtag in the URL

Question

I have a login page on my mean-stack website. The website uses html5mode, and has <base href="/1/" />. The login uses Passport.js, eg:

router.get('/' + process.env.versionNumber + '/auth/google', passport.authenticate('google', { scope: ['https://www.googleapis.com/auth/userinfo.profile',
        'https://www.googleapis.com/auth/userinfo.email'] }));
router.get('/' + process.env.versionNumber + '/auth/google/callback', passport.authenticate('google', {
        successRedirect: '/' + process.env.versionNumber + '/dashboard',
        failureRedirect : '/' + process.env.versionNumber + '/login',
        failureFlash : true
    }))

For Twitter, GitHub and Linkedin, it all redirects to https://localhost:3000/1/dashboard. However, Google redirects to https://localhost:3000/1/dashboard# and Facebook redirects to https://localhost:3000/1/dashboard#_=_.

Does anyone know what's happening?