Gangplank Passive Bug

I believe that when Gangplank builds statik shiv and trinity force and he auto attacks normally while his passive is up with shiv passive ready the auto DOES NOT proc his passive but does proc shiv. You then have to auto again to proc his passive meaning you do not get the true damage burn after you auto the first time. I think you can reproduce this by simply buying statik shiv along with trinity force and then resetting your passive with a barrel.