Version 4.1.0-353-gc741174b3. Running a C Driver test that does the following:

• Drop a collection called "test", ignore errors if the collection doesn't exist
• Call {create: "test"}
• With a new lsid and txnNumber, insert a document into "test"
• Expected: success, the transaction is started and the document is inserted
• Actual: "Unable to acquire lock ' {7905466228821833060: Database, 987937201180751204}

  ' within a max lock request timeout of '5ms' milliseconds."

Same in 4.0.0-rc4. Works if I do not drop the collection immediately beforehand.