We experienced an outage on one server where the CPU data was not collected for a couple days.
The spark chart for this period in List Designer shows a continuous stream of data and does not show any gap, so the outage is not properly reflected in the chart.
This graph should have "gaps" in it, to represent periods where the data is missing.
DX UIM 23.4.2 and prior
The data is being "compressed" down so the gaps do not appear.
This will be resolved in DX UIM 23.4.3 - the spark charts will properly reflect gaps relative to the size of missing data periods.