Microsoft Graph DriveItem permissions no longer returning `link.webUrl`

I’m working on a personal project that integrates with Microsoft Graph to inspect sharing permissions for OneDrive/SharePoint DriveItems.

Previously, when retrieving permissions for a DriveItem using:

GET /drives/{drive-id}/items/{item-id}/permissions

the response for a sharing-link permission included the link.webUrl property, for example:

{
  "id": "...",
  "roles": ["read"],
  "link": {
    "scope": "anonymous",
    "type": "view",
    "webUrl": "https://..."
  }
}

Recently, I started receiving the link object with properties such as scope and type, but webUrl is no longer returned, even though I know that the sharing link exists and is accessible through the DriveItem.

For example, I now receive something similar to:

{
  "id": "...",
  "roles": ["read"],
  "link": {
    "scope": "anonymous",
    "type": "view"
  }
}

According to the Microsoft Graph documentation, link.webUrl is supposed to contain the URL that opens the item in OneDrive/SharePoint.

Was there a recent change in Microsoft Graph that causes link.webUrl to be omitted in some circumstances?

If so:

1. What permissions or authorization conditions are required for link.webUrl to be returned?
2. Is this behavior different between delegated and application permissions?
3. Is there an alternative Microsoft Graph API that can be used to retrieve the actual sharing URL for an existing permission?
4. Is there a supported way to retrieve all sharing links associated with a DriveItem, including their URLs, scope, and type?

I’m particularly interested in retrieving all existing sharing links for a DriveItem for my personal project, rather than creating new sharing links.