Combined selection does not work

Your use case is to target content containing category X AND category Y, instead of category X OR category Y?

Yes, that’s correct.

The AND condition is not working (i.e. is interpreted as OR) when:

• two terms of the same taxonomy are selected
• two terms of two different taxonomies are selected

However, the AND condition is working when e.g. selecting a certain page template AND a certain page (so on page level).

I hope this helps.

The first case is actually intentional, but I might consider changing it.

However, it would lead to some inconsistencies, e.g:
Exposure: Singular & Archive
Condition Group: Category X, Category Y

This would display the sidebar with all content containing X and Y, but it would also display the sidebar with the archive pages for X or Y (by default, you cannot have an archive page for 2 terms).

I will look into the second case, i.e. you want to display a sidebar with Tag X AND Category Y?

Also, the first case is a purely theoretical one – in case of categories. For, categories should – ideally – be mutually exclusive.

However, the second case – display a sidebar with Tag X AND Category Y – is a real life case. It would be nice if you could support this one.