Date Range in Title is not updating to the date range set in the parameter

Hi there Tableau community,

I'm having a strange issue that I can't figure out the cause, and I'm wondering if it's more of a "Data" issue and how Tableau handles "Dates", but looking for assistance and advice on which way to go here to rectify.

Scenario: I am creating a table to show reported labor hours for employees. I have created a parameter to determine the "Date Range" of the report, which seems to work, however in a calculated field that I created to show the "Date Range of report" the Date shows "ALL" instead of the actual Date Range. Unfortunately this is not the case every single time, and when I modify filters to use different employees, sometimes the date shows, and other times it will just say "ALL" and not the actual dates.

My first thought was that this issue was related to the data itself because it's sporadic and doesn't occur on everyone, but I don't know enough about how Tableau reads dates to understand the actual issue.

My calculated field that shows the date is:

My parameter to choose the date is:

My calculated field to utilize the parameter is:

Here are several screenshots of the worksheet with different parameters selected. You can see some worksheets show the proper date range as expected, and others just show "ALL" even though it may or may not be the entire range of dates.

Choose a month = "All Months"

Choose a month = "MAR FY2019"

Choose a month = "Feb FY2019"

Choose a month = "May FY2019"

As you can see in the screenshots, some work as expected (the ones w/ dates are correct as these date ranges are not necessarily the same as calendar start and end...), and others just show "ALL" even though it may or may not be ALL DATES.

I'm curious here on 2 fronts:

1) how does Tableau utilize dates so it knows when to use "ALL" versus the actual date range? I thought that the Min([Dates]) and Max([Dates]) could be extracted at any point, but it doesn't seem so based on what I'm seeing here unless I'm doing something wrong.

I've provided some screenshots that I hope will help, I would prefer not to share the workbook as it has some sensitive data in it.

Boy are Dates in Tableau frustrating!!

Thanks in advance for anyone willing to offer advice or take a stab at this issue.

Dan R