I tried to create a mock QVW but couldn't replicate what I have in my main QVW.
I have a combo chart bar/line with axes totalling 100% Overall it's fine and looks how it should. However when I click on a date which does not have a line value the axes changes from 100% to 1.0. Below is the chart without selections.
The bars are stacked to 100% which is perfect and the lines also show as a percentage.
The problem occurs when I click on a date without a Total field value. For this example I click on dates Aug 16 and Sep 16.
You'll see the axes changes now to 1.0 instead of 100%.
Each bar expression looks like the following for it's respective field.