I assume this is similar to SERVER-21772. This occurs for me when running the Linkbench benchmark with the 3.11 Java driver. I am unable to reproduce this via JS in Mongo shell.

The transaction has ~1000 documents in a bulk write operation. When I disable the use of transactions system.profile gets some inserts. When transactions are enabled it does not get any. The bulk writes are update with upsert=true and ordered=false. 

I have begun instrumenting code and when transactions are disabled then finishCurOp is called and system.profile gets inserts. But I don't see calls to finishCurOp for the bulk writes when done within a transaction.

The other odd thing is that CurOp::_dbprofile == 0 when transactions are used so shouldDBProfile returns false, which explains when system.profile doesn't get inserts. So I assume that a call to enter_inlock is missing, similar to SERVER-21772. Or this occurs because capped collections can't be inserted within a transaction. I am just guessing as I am new to the code.