Some failures have been observed in insert_with_data_size_aware_balancing.js because the balancerCollectionStatus command is returning a balancerComplaint as true when data are not already fairly balanced because numOrphanDocs is read by the balancer while it's stale.

The detailed explanation of why is this happening can be found in the description of SERVER-66835.

A fix suggestion would be to change the test and wait a few more balancer rounds after the balancerComplaint returns true. Another option is to update the numOrphanDocs variable at the same time the range deleter deletes the orphan chunks to avoid stale reads.