I used to receive emails, notifying me when a Review was submitted on a Request, however I am no longer getting them.
This could be caused by a few things. First you'll want to check your Review settings:
Click Admin > Reviews > Global Review Notification Settings Ensure that "Review Submitted Notification" reflects what is shown in this screenshot:
If the Review settings are correct, then it could be due to the Staff person assigned to the Request being someone other than yourself. Only the Staff person (user) will receive the notification emails. Below is a screenshot with an example: