Some of the values not populating in a Table view even though data is expected to be displayed in those cells

Use the ZN function to add the Zero If Null "ZN" to the calculation and that way Null+ a value will return a value and not Null in the cell.
https://help.tableau.com/current/pro/desktop/en-us/functions_functions_number.htm#zn

For Example 



If a cell is intended to show the effect of a calculation where every value in Field 1 is Null and Field 2 contains real values, the following calculation will return Null values.

SUM([Field 1]) + Sum([Field 2])

But if ZN (Zero if null) is added to that calculation, the cells will then display values of Field 2 

SUM(ZN([Field 1])) + Sum(ZN( [Field 2]))