HH:MM:SS Will Not Chart

I am trying to chart data that is in the format HH:MM:SS along the Y-Axis and CallMonth along the X-Axis, and I am not able to do so. The DAX that I am using is below.                     

ACW___Avg =

VAR a = [ACWAvg]

VAR hours = INT ( a / 3600 )

VAR minutes = INT ( MOD ( a - ( hours * 3600 ), 3600 ) / 60 )

VAR seconds = ROUNDUP ( MOD ( MOD ( a - ( hours * 3600 ), 3600 ), 60 ), 0 )

RETURN

TIME ( hours, minutes, seconds )

When I enter this data into a matrix, the data compiles as seen below.

However, when I enter this data into a line graph, the data does not chart. Specifically, when I try putting ‘ACW___Avg’ into ‘Values’ under the ‘Fields’ list under ‘Visualizations’, it does not work. In fact, Power BI puts ‘ACW___Avg’ into ‘Tooltips’ automatically as seen below.

Below is a picture of the line graph that I get -- as you can see, there is no line graph 😞   

Does anyone know how to fix this?

Thanks
Dan