Hi
if you are using an AJO unitary event type trigger then what i normally do is put a trigger on the event table and set a 30 second wait before it does much. So it triggers off the event datastream and waits 30 seconds which gives the profile enough time to stitch into the identity graph. If you are basing it on audiences when it should take more than about 30 minutes for the stream to push into the dataset and stitch, so your 40 minutes makes sense.
in the example above I send the profile and event info at the same time, but the graph needs to update hence the 30 second delay in the AJO journey.