Are site columns automatically searchable in SharePoint Online?

[LetMeSP]

That was always my assumption that site columns are automatically searchable once populated with content. I have a situation where a site column (text) used in a document library is not searchable... Is there anything else I need to do to be able to use values from that column in search? Thanks!

[#2]

Yes, they are sercheable but you might be missing here that you need to create Managed Properties in the search schem to simplify how users can search by column value

[#3]

@Juan Carlos González MartínI now have a Managed Property created and when searching I am seeing the following behavior:

• RefinableString11:[value from the column] -> document found
• [value from the column] -> document not found

Is this expected? What should I do to be able to just enter the value from the column in the search box to find the document?