Nova adds related "through" records without being asked

I have a Nova (4.13) Location resource that loads a related Contract resource via a hasOne relation. This Contract resource has its own hasMany Item records, but for some reason they are showing up in my Location resource view. So when I add this:

HasOne::make('Contract'),

it displays a Contracts section, but also an Items section below it. if I remove the Contract field, both sections disappear.

To clarify, I have this structure:

Location -> Contract -> Item

and Nova is displaying both the Contract and Item sections even though my Location resource only asks for the Contract.

I have another resource that is linked to the same Item records via a different route, and it also pulls in these same records, so if I pull in either one, the Item records for each are brought in too. If I do not pull in either of them, the Item records do not appear.

Nova is acting as if I had also specified a HasManyThrough relation to the Item records.

How do I prevent it from doing that?