Hi Nick,
Note what you have selected as the source of the y values to be charted (cells B2:B11)
Note what you have selected as the source of the x values to be charted (cell A5 )
Note the labels on the x axis of your chart.
Numbers has made avaliant attempt to chart the data you have supplied (one x value, five y values, none of which is paired with the single x value supplied).
There is a single data point charted at x=Oct 28, 2017, y= 01:54.190
I've no explanation how Numbers derived that y value.
Here's the scatter chart constructed using a table with the same values, but with all non-headed cells in column A selected as the x values and all non-header cells in column B selected as the paired y values.
I've made one change to the chart produced—decreasing its height for a better fit here. Other than that, it's shown as it was created by Numbers.

Regards,
Barry