Said it was right where I said it was. In bulkhead compartment.
He found it Weds. Which means it was sitting there from 3:30pm Monday until the plane was shut down for mechanical issues on Weds in SD.
It had flown 17 routes between that time and no one took it or found it.
When I returned to the airport the United gate agent said they went into the plane, looked and it was not there.
Apparently, the agent is either lazy or a liar.