mongoDB $lookup with $search pipeline

I have two collections:

store_group collection:

    {"_id": ObjectId("674fe7cc4e65df54a0db23b5"),"stores": [      {"id": 101, "name":"abc"},  // 101 as int      {"id": 204, "name":"cd"} // 204 as int    ]}

location_view_for_search, a view created from stores collection:

    {"_id": ObjectId("67400d3997214dc99c6311c5"),"location_number": "101", // 101 as String    }    {"_id": ObjectId("67400d3997214dc99c6311c6"),"location_number": "204", // 204 as String    }

I need to lookup store data from store_group, via location_number and apply autocomplete operation on location_number. because the stores._id in store_group collection is number and location_view_for_search.location_number is string, so I first map the number to string, the do the lookup:

    [      {        $addFields:          {            storeIds: {              $map: {                input: "$stores",                in: {                  $toString: "$$this.id"                }              }            }          }      },      {        $lookup:          {            from: "store_view_for_search",            localField: "storeIds",            foreignField: "location_number",            as: "store_details"          }      }    ]

till now it's all working fine, i can see the pipeline output showing the store_details correctly:

    {"stores": [        {"id": 101, "name": "abc"},        {"id": 204, "name": "cd"}      ],"storeIds":["101", "204"],"store_details": [        {"_id": ObjectId("67400d3997214dc99c6311c5"), "location_number": "101"},        {"_id": ObjectId("67400d3997214dc99c6311c6"), "location_number": "204"}      ]    }

next I added $search inside $lookup to apply autocomplete search on location_number in location_view_for_search, i've created the atlas search index to set static mapping on location_number to be autocomplete.

    {        $lookup:          {            from: "location_view_for_search",            localField: "storeIds",            foreignField: "location_number",            as: "store_details",            pipeline: [              {                $search: {                  index:"autocomplete-by-location-number",                  compound: {                    should: [                      {                        autocomplete: {                          query: "572",                          path: "location_number",                          fuzzy: {                            maxEdits: 1,                            prefixLength: 3,                            maxExpansions: 1                          }                        }                      }                    ],                    minimumShouldMatch: 1                  }                }              }            ]          }      }

then all of the sudden the pipeline output showing the store_details in the result as empty array. what did i do wrong? I'm following the mongo tutorial here https://www.mongodb.com/docs/atlas/atlas-search/tutorial/lookup-with-search/.

I've also tested the same $search on location_view_for_search view, it works fine, I can search locations by autocomplete search on location_number