sharepoint online – How Property Mappings Work in the Content Search Web Part

I use the Content Search Web Part to display UAV photos. In the photo below, it shows each building with the name of the file and the date / time of the photo below. I would like to replace the file name with the building number.

I have a column in my library of drone images called building number. I mapped a managed property on the parsed property and confirmed that it is returned in the search results with the help of the SharePoint Query Tool.

The problem is that when I click the Line 1 drop-down list in property mappings, the building number of the managed property does not appear in the list. Does this happen automatically, or do I have to enter the content search Web Part view template?

Thank you

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