Issue modelling date table with dates in other tables

Hi,

I am trying to build a dashboard which lets me have an overview of team performance. I am attempting to create a simple bar chart which shows the number of tasks created over time.

So i'm currently facing an issue where I have a table which has the start date of a task with the task name and ID.

I simply want to connect the start date from that table to the date table so I can slice the count of tasks using the data table. 

However when i try to slice the number of tasks by the data table it just comes up blank.

So you can see here, I have 58 tasks that slice when i use the start date of the same table

But, when i slice with the data table it says blank despite the start dates falling within that parameter

Same thing here when i use the date table date on a bar chart no data is showing

Can anyone help me understand why the date table isn't functioning as I intend it to? 

Thank you,

Yoshi