The way it works with paypal is:
You submit a subscription payment.
Then paypal sends this site a notification when it is paid.
Once paid this site will grant permissions to that user.
In case there are any glitches like connection issues between paypal and this site , paypal tries multiple times for 5 days.
All of this happens with no human intervention.

Usually it is just moments to process but sometimes it can take a few minutes or up to a couple of days to complete.
This process is out of our control.
It is up to internet connectivity with paypal and this site and where the funds come from..

Then sometimes it is your browser cache that just needs a bit of time to update your cookie setting.