@ErikG It looks like the “Missing Data” option doesn’t work if both the date on the x-axis and the value on the y-axis are missing. The “Show date gaps” option just adds the missing dates at the visual level. For the “Missing Data” option to work, all the months have to be in the dataset even if they don’t have any value.
@Rad
Are you able to join with a date dimension table that contains all dates in your date range? When you create your visual, put the date from the date dimension table on your x-axis. The “Missing Data” option will work if you do that.