How to properly set up a smart filter in bitrix to filter by a custom property?

Question

1C-Bitrix

Hello dear friends, the essence of the problem is as follows. The smart filter works and works well, but there is one problem that I can’t solve in any way. The point is the following.
1) There is a custom property "Sale", it has one value, Yes.
2) The display of this property in the smart filter is set to checkbox.
3) When we go to a section where there is at least one product with the "Sale" property set to Yes, the filter works correctly.
3) When we enter a section where there is not a single product with the "Sale" property set, the following happens:
When the "Sale" property is selected, the filter displays "88 products found" (that is, all products of the current section. Although, logically,
Please advise how to fix this error. Thanks...

Answer 1

The ID of the current section is most likely not passed to the smart filter, so it searches the entire directory with Ajax and displays the result.
See the component settings, there should be a field for section substitution