Line and Clustered Column Chart Skipping Values

Hello,

Does anyone know why the Line and Clustered Column Chart is skipping some columns? Is there some visual customization I can change? 

In my below case, each 1 leak test should be paired by one total leak test for the day however, on the chart, some 1 leak test omits the total leak test pair. The chart on the bottom comfirms there are indeed total leak test values for that day.