queryoptimizer3.js has a parallel thread running periodic drop collection commands. The rest of the test is performing reads and further drops. In the sharding suites, this test keeps running into LockBusy. This is because the cluster drop collection command takes distlocks, whereas the shard drop collection command does not.

Some of the failing suites: causally_consistent_jscore_passthrough_WT, sharding_jscore_passthrough_WT, sharding_jscore_op_query_passthrough_WT, sharding_jscore_passthrough_wire_ops_WT, concurrency_sharded_causal_consistency_and_balancer, sharded_collections_jscore_passthrough_WT