Number of path views between two pages changes depending on which page is the focus

[Huntp]

I have two pages. One is my homepage and the second is my product page. I have created a flow visualisation with the homepage as the dimension in the middle. One of the journeys out of this dimension is to the product page which has 1,471 path views.

I have created a second flow visualisation, this time focusing on the product page. Looking at the journeys into this page the number of path views coming from the home homepage is 765. Surely as these are the same journey this number should be the same?