Power Bi Report Builder

I have a PowerBi data set with two tables that I've published to PowerBi and trying to use in PowerBi Report Builder

• BillingTable: Student Name|Date of Service|Grade|School District|Attendance Code|Address etc...
• CalendarTable: Date|Month|Day of the Week etc...
  • This date table uses distinct values from the Date of Service in the BillingTable to make the Date Column
• There is a relationship between BillingTable [Date of Service] and CalendarTable [Date]

This is where the issue is...In Report Builder I have a Tablix that has the Dates of Service in the Columns.  Student Name and Grade in the Rows.  For each student, it shows the Attendance code for each date.  The Table below is a sample....this would be dates all the way up to 11/30/23 if continued...

This works great if I'm looking at everyone on one report. 

But....

I have a page break after every instance of a new School District so that students from those districts are displayed and grouped on that page.  This works great when I have multiple students and all possible dates are represented in the Columns.  The issue is where I have a student (who maybe is the only student at that district) that has maybe started or left halfway through the month or attendance wasn't taken at all on a day....those dates will not show at the top.  When I try to use my date table so I can show all possible dates, it tells me "only fields from DataSet1 can be used"

In the scenario below, this student is the only student at this school district and was only here for part of the month (Discharged at the end of the day on 11/5/23).  Only the data between 11/1/23 - 11/5/23 shows.  The issue is, If I was running the same range as above, I'm missing the 8th,9th, and 10th.  In addition, 11/4/23 never had data taken, but doesn't show.  Appreciate anyone who can point me in the right direction, this one is driving me nuts....I feel like there is an easy fix I'm not seeing

Current Result: 

Desired Result: