Bar chart in Vaadin Charts doesn't seem to respect the dateformat if all the data in the DataSeries is for the same month?

Question

If my DataSeries is spread over multiple months then everything works as expected, however if all the data is within a single month it displays a weird x axis label. My code is:

configuration.getxAxis().setType(AxisType.DATETIME);
configuration.getxAxis().setDateTimeLabelFormats(new DateTimeLabelFormats("%b %Y", "%Y")); 

I've attached a screenshot to show what I mean. For that chart I have 3 items in the DataSeries, all for the month of Jan 2018. The format I'd like is Jan 2018 on the x-axis