error in MongoDB QAN explain

User Impact: User gets "default addr for network 'mongodb://127.0.0.1:27017' unknown" error message in mongodb Explain. 

STR:

Was able to Reproduce this with PMM 2.9.1 MongoDb explain loads and then start showing the above-mentioned error. 

Attaching the Gif for recreation of Scenario with PMM 2.9.1 Mongo 4.x, the steps to recreate are the following: 

1) Setup PMM 2.9.1 with MongoDB 4.2, enable QAN 
2) Open QAN, set Time Range to the past 1 hours.
3) Find Distinct Query for MongoDb and Click on it to view Explain in Detail Section. 
4) Explain is loaded and then starts showing the error message. 

STR2:

Looks like the issue is reproducible for any query type but only with the very first selected query on page. With page refresh or on details section close or navigation to another page it could be repeated again (see default_err2.gif)

Actual Result:
default addr for network 'mongodb://127.0.0.1:27017

Expected Result:
This explain message is confusing and should be fixed, the error makes no sense.

Original report:

When trying to see explain plan for MongoDB queries in the QAN section, the following error is displayed:

default addr for network 'mongodb://127.0.0.1:27017' unknown

This was validated on pmmdemo.percona.com environment