I've been experiencing a strange bug in my Sourcetree installation, wherein my commits are not lining up with my graph, like so:

In the above image, I have the pink head commit selected; I seem to recall that, in the past, the blue highlighted region would be centered on the selected commit in the graph. However, lately, my Sourcetree program has been displaying the nodes a noticeable amount upwards, on all repositories, over multiple times opening the program, and multiple times entirely powering the computer on/off, with no visible change.
I haven't been able to easily locate anyone experiencing any similar problems, so is my issue an isolated error, and does anyone know how to fix it? It's really been starting to bug me.