Date Runtime Parameter error when adding filters in the dashboard

In my Postgres query I have something a filter like this:

 $c9_calendarstart$('2021-01-01')$[Calendar Start]${date|yyyy-MM-dd}$ 

I use it in a couple of places throughout the query, and it works perfectly with whatever default value I choose. 

I can add the grid widget created by this query to a dashboard and it also works perfectly, but the thing is it throws an error when I add the dashboard date filter. I see the field I created with the query parameter, I choose "Equal" as condition type (because it's a single date), and then tried many possible values (from relative values like Today or This month, to custom values like Dec 20, 2021). 

Is there something I'm missing?

Cheers and happy holiday season!