The issue is related to https://mantis.opcfoundation.org/view.php?id=6160

See the Note: https://mantis.opcfoundation.org/view.php?id=6160#c15668
TreatUncertainAsBad = true, and Simple Bounding resulting in data for the interval being??
[0] 01:20.000Z, Null, BadNoData (0x809b0000)

According to the specification - 5.4.3.36 WorstQuality2:
The last statement in the first paragraph: The server shall ignore the TreatUncertainAsBad for this aggregate.
Therefore, the Raw data with Uncertain StatusCode is NOT Bad.

If you consider the above statement,

• if the value before timestamp is non-Bad then it is the bounding value → YES (70 - Uncertain)
• If the value before the timestamp is Uncertain the StatusCode is Uncertain_DataSubNormal. → YES (Uncertain)

The Simple Bounding resulting in data for the interval
01:20.000Z, 70, UncertainDataSubNormal (0x40a40402)