Prosite settings not working properly


I am badly stuck on multiple points after setting up pro sites, and needs help. Let me try to explain the 2 main issues:
1. once a user selects a plan from pro site checkout and goes through paypal payments, the user is redirected to a page wherein the login details are shown and admin url is shown that of primary site, and not of a subsite that the user registered for. Please see the screenshot below.

2. After making payments, the user gets no notification whatsoever of payments and his admin details.

I guess I am missing some setting somewhere. Maybe you can point me to the right direction.