I'm new to MongoDB and took some courses at the MongoDB University.
When it came to Jumbo chunks I played around with it, but it behaves strange to me.
I intentionally created a jumbo chunk and it is treated as it should be treated
(not split even if it could by inserting another shard key value, not splittable manually except after adding another shard key value).
But it is not marked as jumbo, neither in the respecitve table, nor in the sh.status() output.
 
At https://discourse.university.mongodb.com/t/divisible-jumbo-chunks I already wrote detailed information and log file excerpts.
Can you tell me why this chunk is not marked as jumbo?
Is this a bug?
 
PS: version is 3.4.2 because that is the version in the vagrant box of the university course