Issue with drive items search indexing

Question

We are using the Microsoft Graph API of POST search/query since Nov 2020 for searching excel and other files in the OneDrive account. This was working fine until a couple of weeks back. Now whenever we add a new file to our OneDrive account, it should show up in the response list of the search query request, but it doesn’t. Some of the old existing files also doesn’t show up in the response as well. These are some critical errors for our process, that needs to be addressed asap.

API information used:
Graph Explorer: https://developer.microsoft.com/en-us/graph/graph-explorer
Request method: POST
Request URL: https://graph.microsoft.com/v1.0/search/query
Request Body:
{
"requests": [
{
"entityTypes": ["driveItem"],
"query": {
"queryString": "path:https://scitara-my.sharepoint.com/personal/sylvester_das_scitara_com/Documents isDocument=true filetype:txt"
},
"fields": ["id", "name"],
"sortProperties": [
{ "name": "lastModifiedDateTime", "isDescending": "true" }
],
"from": 0,
"size": 25
}
]
}