Need help on history aggregation mode


I face some issue with history aggregation mode. I have a tag with steady value of 100 all the time.

When I try to get minimum, maximum and range of the signal in time range it return 100 for all of them.
I wonder why it return 100 instead of 0 for range aggregation mode???
I define signal with following setting:

I also try to enable prevent interpolation and get Null for Range.
Could some one please help me and tell what is happening here.

It seems the interpolation doesn’t work correctly. The aggregation analyse only work with real record not interpolation value. I wonder it’s a bug or I miss something here.

Here is another example with even available record but still wrong result: