Report Filters Not Responsive

I've created a helper column in my sheet for parent/child relationships, which assigns it a number based on this formula:

=COUNT(ANCESTORS([SOW Item or Task]@row)) + IF(COUNT(CHILDREN([SOW Item or Task]@row)) > 0, "+", "")

In my report, I've created a filter to allow for all numbers except 1+:

However, the report is not showing row level 0 items, even when they match all other criteria:

In the above report screenshot, the only items showing up are level 1, 0+, and 2, but not 0.

What do I need to fix to resolve this?