diff --git a/backend/connector_v2/serializers.py b/backend/connector_v2/serializers.py
index 5517bc525..86e873480 100644
--- a/backend/connector_v2/serializers.py
+++ b/backend/connector_v2/serializers.py
@@ -53,10 +53,10 @@ def save(self, **kwargs):  # type: ignore
                     oauth_credentials=kwargs[CIKey.CONNECTOR_METADATA],
                 )
                 kwargs[CIKey.CONNECTOR_AUTH] = connector_oauth
-                (
-                    kwargs[CIKey.CONNECTOR_METADATA],
-                    refresh_status,
-                ) = connector_oauth.get_and_refresh_tokens()
+                # Discard return value: ConnectorAuth.extra_data is shared across
+                # every connector with the same (provider, uid) and would overwrite
+                # this connector's form fields (site_url, drive_id).
+                connector_oauth.get_and_refresh_tokens()
             except Exception as exc:
                 logger.error(
                     "Error while obtaining ConnectorAuth for connector id "
diff --git a/backend/connector_v2/views.py b/backend/connector_v2/views.py
index 09a33be98..a8268acb3 100644
--- a/backend/connector_v2/views.py
+++ b/backend/connector_v2/views.py
@@ -90,12 +90,15 @@ def _get_connector_metadata(self, connector_id: str) -> dict[str, str] | None:
 
         # Only use OAuth flow if connector supports it AND oauth_key is provided
         if ConnectorInstance.supportsOAuth(connector_id=connector_id) and oauth_key:
-            connector_metadata = ConnectorAuthHelper.get_oauth_creds_from_cache(
+            oauth_tokens = ConnectorAuthHelper.get_oauth_creds_from_cache(
                 cache_key=oauth_key,
                 delete_key=False,  # Don't delete yet - wait for successful operation
             )
-            if connector_metadata is None:
+            if oauth_tokens is None:
                 raise MissingParamException(param=ConnectorAuthKey.OAUTH_KEY)
+            # Preserve non-secret form fields (e.g. site_url connector Sharepoint)
+            form_metadata = self.request.data.get(CIKey.CONNECTOR_METADATA) or {}
+            connector_metadata = {**form_metadata, **oauth_tokens}
         else:
             connector_metadata = self.request.data.get(CIKey.CONNECTOR_METADATA)
         return connector_metadata
diff --git a/unstract/connectors/src/unstract/connectors/filesystems/sharepoint/sharepoint.py b/unstract/connectors/src/unstract/connectors/filesystems/sharepoint/sharepoint.py
index 3eacdac30..e8acd44f3 100644
--- a/unstract/connectors/src/unstract/connectors/filesystems/sharepoint/sharepoint.py
+++ b/unstract/connectors/src/unstract/connectors/filesystems/sharepoint/sharepoint.py
@@ -137,8 +137,8 @@ def _get_drive(self) -> Any:
             ctx = self._get_context()
 
             if self.drive_id:
-                # Specific drive by ID
-                self._drive = ctx.drives.get_by_id(self.drive_id)
+                # Specific drive by ID — EntityCollection uses bracket indexing.
+                self._drive = ctx.drives[self.drive_id]
             elif self.site_url and "sharepoint.com" in self.site_url.lower():
                 # SharePoint site - get default document library
                 self._drive = self._get_sharepoint_site_drive(ctx)
@@ -149,15 +149,15 @@ def _get_drive(self) -> Any:
         return self._drive
 
     def _get_sharepoint_site_drive(self, ctx: Any) -> Any:
-        """Get drive from SharePoint site URL."""
+        """Get drive from SharePoint site URL.
+
+        Uses the library's get_by_url, which maps an absolute site URL to the
+        Graph API's ``/sites/{hostname}:/{server-relative-path}`` addressing.
+        """
         from urllib.parse import urlparse
 
-        parsed = urlparse(self.site_url)
-        # Extract site path from URL like
-        # https://tenant.sharepoint.com/sites/sitename
-        site_path = parsed.path.rstrip("/")
-        if site_path:
-            return ctx.sites.get_by_path(site_path).drive
+        if urlparse(self.site_url).path.strip("/"):
+            return ctx.sites.get_by_url(self.site_url).drive
         return ctx.sites.root.drive
 
     def _get_onedrive_drive(self, ctx: Any) -> Any:
diff --git a/unstract/connectors/src/unstract/connectors/filesystems/sharepoint/static/json_schema.json b/unstract/connectors/src/unstract/connectors/filesystems/sharepoint/static/json_schema.json
index d83f84c8a..6070cbd84 100644
--- a/unstract/connectors/src/unstract/connectors/filesystems/sharepoint/static/json_schema.json
+++ b/unstract/connectors/src/unstract/connectors/filesystems/sharepoint/static/json_schema.json
@@ -63,8 +63,7 @@
             "user_email": {
               "type": "string",
               "title": "User Email",
-              "format": "password",
-              "description": "User's email address. Required ONLY for OneDrive with Client Credentials (not needed for SharePoint).",
+              "description": "Required only to access OneDrive with Client Credentials (e.g., user@company.com). Leave empty when accessing a SharePoint site via Site URL.",
               "examples": [
                 "user@company.onmicrosoft.com",
                 "user@company.com"