Root Cause: Real time reports do not support Page Views metric. This behavior is working as designed. Due to which there are limitations on the types of data that can be accessed. The "page views" is not supported in real-time (that metric is calculated on a dimension basis later in the processing pipeline). Thus, when any dimensions are at play in real-time, users only gets instances which can't be changed.
Validation: When you request for "page views" metric in Real Time API , it returns "Instances" metric in response.
This behavior can't be changed currently as it can break current implementations and would need code changes.
API Request where you request for Page Views metric