Line Chart

Hi,

I am trying to build a report that shows how much we have billed last year and this year.

I imported two of the same table:

First table I filtered the invoice date for last year

The second table I filtered the invoice date for this year

Problem is, when I draw a simple line graph to compare the two years, this year's line comes as a straight line whereas it should be fluctuating

Additionally, on the x-axis, powerbi is skipping a month and I don't have the option to drill down.  Please see screenshot attached

Does someone know how to rectify this?