Current BI Connector behaviour is that it will do a listCollections command after an existing connection to BIC has been idle for 1-2 minutes. For databases with thousands of collections, this will take several minutes to complete. Afte rthe connection to BIC has been idle for a few minutes, the connection from BIC to MongoDB is dropped and when a new connection is created, the listCollecion command is called again. This overhead is unnecessary.
Request to have an option to keep the connection alive or some form of connection pooling mechanism so that listCollection will not be called over and over again.

Support case for reference: https://support.mongodb.com/case/01189673