This is kind of a weird one and not a huge issue as it resolves itself as soon as the binding for the dataset updates again. Whenever I go to another tab in my browser, it's almost as if the xy chart continues to render the datasets, but doesn't clear the chart whenever it renders the line again. Then whenever I go back to the tab, all the data that has come in since I left the page is rendered at the same time. Here is an example of what it looks like with several updates worth of data rendered on top of each other and then another example of what it looks like when it updates again. Not really sure if this is a bug or if I am missing some configuration that would cause this.
I've seen a few posts regarding issues with the XY charts when you are using a binding for the data series, but this seems slightly different than those issues posted. Wondering if anyone has seen anything like this previously.