I've noticed a bug in Desktop and Service when using the 'show items with no data' functionality on an X axis, if the axis is long (so it has a scroll bar) then lines are rendered between the 2 points where data actually exists (like a continuous line on a date axis) although there should be a gap. This only happens when there are more than one item on the chart - 2 examples below.
Example 1 - all okay, there is a break in the line as expected.
Example 2 - lines are drawn where there are no data (when displaying more than one line).
Both lines in example 2 should have gaps. This only happens when the scroll bar is visible and setting the axis as below.
Example 3 - all lines should have a gap like the lower line because there are no data.