Power BI - Slicer Dropdown Default Date

I have a date filter on my page. I created a true/false value table (Table 2) and a measure to get the most recent date on my dropdown filter. I used the Preselected Slicer to create the visual with Fields = Date, Pre Selection = Measure, and Dirty Status = Table. I then set the Format Display as Dropdown. 

Table 2 = {TRUE(),FALSE()}

Measure = var a=MAXX(ALL('Table'),[Column1])

return IF(MAX([Column1])=a,TRUE())

All of this worked  - in that the dropdown slicer does display the most recent date BUT only the most recent date shows on the slicer. How can I get the slicer to list all the dates, allowing the user to change the date to an earlier date? I want it to continue to to default to the most recent date as data is added or as user click in/out of the link/dashboard?