If any of the queries in an array formula do not have actual data to query in the range they are hitting they return #VALUE!
and mousing over the array formula reveals an error. If I take those queries and wrap them in an IFERROR I get the same results.
If I take what I wrapped in an IFERROR and split it out into its own cell to validate the query it results in displaying the error clause which in this case is a 0.
Here is a link to an example sheet.
Sheet1 has sample data.
Sheet2 is intentionally blank to simulate the issue described above.
Sheet3 has three queries on it in various states. The top two are the array formulas I am attempting to work with. The bottom Query is the IFERROR split out into its own cell to show that the query does in fact work when separated from the rest of the sort(arrayformula(etc)).