in the following Overpass QL query I can either comment out line #3 or not. When leaving it, I get the result of a search focused on one relation number. When commenting it out, I get the result of the same search, based on an area rather than a relation number.
What I don’t understand is why the ~1000-long list of relations returned by the area-based query does not include the one relation. The other query proves that the relation matches the criteria, and that it is located in the area. So why is it not included in the list?
This help forum post is old but I believe still relevant (public transport “route master” relations are usually similar in that they only contain other relations):