Having issues with Day of Week in a table (showin numbers and not grouping)

I have two tables and a blend with those two.

The first one has session ID, Date and other fields

The second one has Session ID, minutes, and other fields

If I create a visual using just the first table and date and record count and on date using day of week it works perfectly fine

But when trying to do the same with the blend it makes something weird with the days, it creates a line for each register in the first table.

If I use any other dimension on the blend it works great, doesn’t matter if the dimension comes from first or second table, here you can see one of the blend with a dimension from second table grouping correctly. It works with any field except date.

What am I doing wrong for the date dimension

Thanks for any help