Description
The Distance Interval parameter value with which the Template Cube value was created may vary slightly from the resulting Output Space Time Cube value.
If you created the Template Cube value with a version earlier than ArcGIS Pro 2.1 with a Distance Interval parameter value using the unit of measure feet, the unit feet used was International Feet. This has changed at ArcGIS Pro 2.1, which has been updated to use the unit US Feet. This will cause slight differences in the grid cell size between the Template Cube value created using International Feet and the Output Space Time Cube value using US Feet.
However, if the spatial reference of the Template Cube parameter value uses US Feet, there will be no change.
Solution
Re-create the Template Cube value using ArcGIS Pro 2.1 or later.