diff --git a/frontend/app/api/mutations/useConnectConnectorMutation.ts b/frontend/app/api/mutations/useConnectConnectorMutation.ts
index 893a90086..afb0cc46a 100644
--- a/frontend/app/api/mutations/useConnectConnectorMutation.ts
+++ b/frontend/app/api/mutations/useConnectConnectorMutation.ts
@@ -77,7 +77,8 @@ export const useConnectConnectorMutation = () => {
             result.oauth_config.redirect_uri,
           )}&` +
           `access_type=offline&` +
-          `prompt=select_account&` +
+          `include_granted_scopes=true&` +
+          `prompt=consent&` +
           `state=${result.connection_id}`;
 
         window.location.href = authUrl;
diff --git a/frontend/contexts/auth-context.tsx b/frontend/contexts/auth-context.tsx
index 004045314..4552e6eb9 100644
--- a/frontend/contexts/auth-context.tsx
+++ b/frontend/contexts/auth-context.tsx
@@ -132,7 +132,8 @@ export function AuthProvider({ children }: AuthProviderProps) {
             `scope=${result.oauth_config.scopes.join(" ")}&` +
             `redirect_uri=${encodeURIComponent(result.oauth_config.redirect_uri)}&` +
             `access_type=offline&` +
-            `prompt=select_account&` +
+            `include_granted_scopes=true&` +
+            `prompt=consent&` +
             `state=${result.connection_id}`;
 
           console.log("Redirecting to OAuth URL:", authUrl);
diff --git a/src/connectors/google_drive/oauth.py b/src/connectors/google_drive/oauth.py
index e9beb0a36..0c33102ba 100644
--- a/src/connectors/google_drive/oauth.py
+++ b/src/connectors/google_drive/oauth.py
@@ -1,6 +1,7 @@
 import os
 import json
 from typing import Optional
+from datetime import datetime, timezone
 from google.auth.transport.requests import Request
 from google.oauth2.credentials import Credentials
 from google_auth_oauthlib.flow import Flow
@@ -50,13 +51,18 @@ async def load_credentials(self) -> Optional[Credentials]:
                 scopes=token_data.get("scopes", self.SCOPES),
             )
 
-            # Set expiry if available (ensure timezone-naive for Google auth compatibility)
+            # Set expiry if available.
+            # Backward compatibility: older tokens were saved as naive local datetimes.
             if token_data.get("expiry"):
-                from datetime import datetime
-
                 expiry_dt = datetime.fromisoformat(token_data["expiry"])
-                # Remove timezone info to make it naive (Google auth expects naive datetimes)
-                self.creds.expiry = expiry_dt.replace(tzinfo=None)
+                if expiry_dt.tzinfo is None:
+                    local_tz = datetime.now().astimezone().tzinfo
+                    expiry_dt = expiry_dt.replace(tzinfo=local_tz)
+
+                # google-auth compares against a naive UTC timestamp internally.
+                self.creds.expiry = (
+                    expiry_dt.astimezone(timezone.utc).replace(tzinfo=None)
+                )
 
         # If credentials are expired, refresh them
         if self.creds and self.creds.expired and self.creds.refresh_token:
diff --git a/src/services/auth_service.py b/src/services/auth_service.py
index d2fe43971..77e135e1b 100644
--- a/src/services/auth_service.py
+++ b/src/services/auth_service.py
@@ -4,7 +4,7 @@
 import httpx
 import aiofiles
 import logging
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 from typing import Optional
 import asyncio
 
@@ -92,7 +92,6 @@ async def init_oauth(
         )
 
         # Get OAuth configuration from connector and OAuth classes
-        import os
 
         # Map connector types to their connector and OAuth classes
         connector_class_map = {
@@ -236,21 +235,36 @@ async def handle_oauth_callback(
                 else granted_scopes
             )
 
+            refresh_token = token_data.get("refresh_token")
+            token_file_path = connection_config.config["token_file"]
+
+            # Some OAuth providers omit refresh_token on re-consent. Preserve an
+            # existing one so background token refresh keeps working.
+            if not refresh_token and os.path.exists(token_file_path):
+                try:
+                    async with aiofiles.open(token_file_path, "r") as f:
+                        existing = json.loads(await f.read())
+                    refresh_token = existing.get("refresh_token")
+                except Exception:
+                    refresh_token = None
+
             token_file_data = {
                 "token": token_data["access_token"],
-                "refresh_token": token_data.get("refresh_token"),
+                "refresh_token": refresh_token,
                 "scopes": scopes,
             }
 
+            if token_data.get("id_token"):
+                token_file_data["id_token"] = token_data["id_token"]
+
             # Add expiry if provided
             if token_data.get("expires_in"):
-                expiry = datetime.now() + timedelta(
+                expiry = datetime.now(timezone.utc) + timedelta(
                     seconds=int(token_data["expires_in"])
                 )
                 token_file_data["expiry"] = expiry.isoformat()
 
             # Save tokens to file
-            token_file_path = connection_config.config["token_file"]
             async with aiofiles.open(token_file_path, "w") as f:
                 await f.write(json.dumps(token_file_data, indent=2))