Power BI stacked column chart values change incorrectly when multiple selections are made in the slicer

I have a stacked column chart in Power BI showing hours worked per staff on respective tasks.

1. Table: Tasks

2. Fields:

   • X-axis: Tasks[EmpName]

   • Values: Tasks[totalhrs] / 7

   • Legend: Tasks[Taskname]

3. Slicer: Tasks[EmpName]

4. Problem
   When a single employee is selected the chart shows correct slicers.

   But when multiple employees are selected the number drop down.
   Eg. Emp 1 shows 37 hours when selected alone but when Emp 2 is selected it drops to 17 hours
   The other charts work perfectly fine, the problem appears only in this stacked column chart.
   I have tried creating a measure like DIVIDE(SUM(Tasks[totalhrs]),7) using All Except to lock to EmpName and have also used Max and Selected value but it does not seem to work.

   The values in the stacked column chart display correctly when the legend is removed, but I need to keep the legend to show the Tasks performed. Can someone please advice?