Hi @JD14 ,
Since your CompStatus column is not a Number column, you cannot directly use "CompStatus/Sum(DirectReporteeCol,CompStatus)*100" to get the percentage. You can check the Percentage column inside collection DirectReporteeCol, it should be 0.0%. (also "Sum(DirectReporteeCol,CompStatus)" cannot get correct value, you should use CountRows function)
So for your requirement, you can create a new collection including a table with CompStatus column and Number column(numbers of same CompStatus value). I did a test on my side, you can refer to my steps:
1. Here is my collection with 7 records:

2. Add a button with below formula to create a new collection called "colchart"(replace with your own CompStatus value):
ClearCollect(colchart,
Table( {CompStatus:"Agree",Number:CountRows(Filter(DirectReporteeCol,CompStatus="Agree"))/CountRows(DirectReporteeCol)},
{CompStatus:"Disagree",Number:CountRows(Filter(DirectReporteeCol,CompStatus="Disagree"))/CountRows(DirectReporteeCol)},
{CompStatus:"Strongly Agree",Number:CountRows(Filter(DirectReporteeCol,CompStatus="Strongly Agree"))/CountRows(DirectReporteeCol)},
{CompStatus:"Strongly Disagree",Number:CountRows(Filter(DirectReporteeCol,CompStatus="Strongly Disagree"))/CountRows(DirectReporteeCol)}
)
)

3. Set items property of PieChart control to:
AddColumns(colchart,"percentage",Text(Number*100,"[$-en-GB]##0.0%"))

4. Set Items property of Legend control to:
colchart.CompStatus

5. Open Advanced tab of PieChart control, and select “percentage” option of Labels dropdown:

Check result this time:

Best regards,
Allen