Sorting visual by a "date" that is text based.

PowerBINoob24 

You don't sort the table by the [test sort] column.   You set the sort order for the column you are showing in the x axis using [test sort] column.

In the table view.

Select the column you are showing in the x axis.

Go to the 'Sort by column' drop down and pick the [test sort] column.

You are telling PowerBI 'Sort this column I have clicked on using the values in this other column I pick in the drop down'

https://learn.microsoft.com/en-us/power-bi/create-reports/desktop-sort-by-column?tabs=powerbi-desktop