The box will never remain water tight. Drill a hole on the bottom to let the water out. You need to wrap the connection in coax seal/ silicon tape and/or use the waterproof connectors included with some cams. If you simply left the connection exposed, that would explain the failure. Sometimes the cameras will work if your clean/replace the connector. Sometimes the POE module is fried but it will work with 12v. Other times the camera is just dead.