As discovered in this ticket and discussed in this [CR|https://mongodbcr.appspot.com/799100006.] The transaction in ShardingCatalogManager that makes sure the updates in
bumpCollectionVersionAndChangeMetadataInTxn happen atomically requires at least 5 GB of Wired Tiger cache size.
This is too large for an Atlas M30 to be able to handle as it has 8 GB of RAM and 50% of it is used for WT cache.
We need to investigate whether this is an issue and how to fix it.