Q:

Firestore doesn't immediately start listening to changes when Internet Connection Resumes

If I start the app without Internet connection, and then turn on internet, Firestore takes some time before it starts listening to changes.  Can this behavior be changed?  Like can it start listening to changes as soon as Internet connection resumes. 

A:

You currently don't have any control over how the Firestore SDK manages its connections. 
Most code that performs retries do so with an exponential backoff algorithm.   This prevents the retries from happening so quickly that it impairs the performance of the host app, and also possibly consuming too much of the user's data plan.   However, this means that it may take some time to regain the connection.