I'm hoping that this isn't too obvious but I've noticed this situation several times and have had to work around it.
I have a situation where the output of a FILTER function is creating a "0" (Zero) when the input cell is blank. I' tested for possible spaces or a real zero in the source and come up dry. The source really is a null.
The end result is when I go to compare the contents of the output cell in a SUMIFS there is a no-match situation and the values I need are not added into the sum.
As long as the source cell has anything in it, other than a null, all is good.
I've seen this before but have yet to find an answer.
This is the formula I'm using to create the data I need. The Cell in question is Transactions!Expense_Sub_Center. When if is Null or empty I get a zero-entry in the output cell.