Graph REST API - Search inside DriveItem not working for non-mainstream file extensions - microsoft-graph-api

Question

I've been trying to search within a specific DriveItem folder but I've been having some troubles. First of all, despite the API stating that "You can search within a folder hierarchy, a whole drive, or files shared with the current user.", I haven't found any documentation supporting this. I have found this stackoverflow reply that describes how to do it. Unfortunately, it doesn't to be working very well.
Since I don't know how sensitive IDs are, I'll be redacting them in my examples.
https://graph.microsoft.com/v1.0/me/drive/items/<id_parent_folder>/children?select=name
This request returns all files inside the folder I want to search and it does list everything inside the folder. The response is something like:
{
"#odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('<id_user>')/drive/items('<id_parent_folder>')/children(name)",
"value": [
{
"#odata.etag": "\"{redacted1},1\"",
"name": "automation_csv.csv"
},
{
"#odata.etag": "\"{redacted2},1\"",
"name": "HOSPITAIS_PT.cpg"
},
{
"#odata.etag": "\"{redacted3},1\"",
"name": "HOSPITAIS_PT.dbf"
},
{
"#odata.etag": "\"{redacted4},1\"",
"name": "HOSPITAIS_PT.prj"
},
{
"#odata.etag": "\"{redacted5},1\"",
"name": "HOSPITAIS_PT.qpj"
},
{
"#odata.etag": "\"{redacted6},1\"",
"name": "HOSPITAIS_PT.shp"
},
{
"#odata.etag": "\"{redacted7},1\"",
"name": "HOSPITAIS_PT.shx"
}
]
}
However, when searching inside the folder I only get the CSV file....
https://graph.microsoft.com/v1.0/me/drive/items/<id_parent_folder>/search(q='')?select=name
{
"#odata.context": "https://graph.microsoft.com/v1.0/$metadata#Collection(driveItem)",
"value": [
{
"#odata.type": "#microsoft.graph.driveItem",
"name": "<name_parent_folder>"
},
{
"#odata.type": "#microsoft.graph.driveItem",
"name": "automation_csv.csv"
}
]
}
Searching for any other file name produces no results.
Is this a bug or a feature? Is there another endpoint that allows me to search all files inside a folder?
EDIT: changed the "beta" endpoint to "v1.0", though they produce the same results. Just don't want to create the assumption that it only happens in the beta endpoint.

Answer 1

Use the Microsoft Query API to search instead of using q search parameter.
See https://learn.microsoft.com/en-us/graph/api/resources/search-api-overview?view=graph-rest-beta