milestone:passageList:"topic:Marriage in ESV" produces far more verse results than the Passage List itself, which comes from the "Default reference matching" query topic:Marriage in ESV.
The milestone query expands a chapter into all its verses e.g. Gen 9 ---> Gen 9:1-29 and the Passage List also has Gen 9:1-17 (17 verses). When the chapters are removed from the Passage List the query has the same number of verses.
Any PL with chapter numbers and verses from the same chapter will produce this result. My opinion is that the chapter number should be ignored if this is the case. A range of verses causes no problems if it duplicates individual verses in the PL i.e. the range is effectively ignored.
Note that the erroneous (IMHO) chapter numbers in the "Default" Topic query come from preachingTheme:Marriage.
.
Milestone by Chapter
If the PL contains:
Gen 9:1-12
Gen 9:1
Gen 9:2
...
...
Gen 9:17
Gen 9:18-20
The milestone Bible query by Chapter counts 7 results and highlights Gen 9:1-20 in the bible.
(A Books Search also counts 7 and highlights Gen 9:1-20 in the bible)
The Bible query by Verse correctly counts 20 verses and highlights Gen 9:1-20 in the bible.
