diff --git a/api/models/schema/userSchema.js b/api/models/schema/userSchema.js
index ec4a1ef865..d2b30e1c37 100644
--- a/api/models/schema/userSchema.js
+++ b/api/models/schema/userSchema.js
@@ -84,28 +84,31 @@ const userSchema = mongoose.Schema(
     },
     googleId: {
       type: String,
+      index: true,
     },
     facebookId: {
       type: String,
+      index: true,
     },
     openidId: {
       type: String,
+      index: true,
     },
     ldapId: {
       type: String,
-      unique: true,
-      sparse: true,
+      index: true,
     },
     githubId: {
       type: String,
+      index: true,
     },
     discordId: {
       type: String,
+      index: true,
     },
     appleId: {
       type: String,
-      unique: true,
-      sparse: true,
+      index: true,
     },
     plugins: {
       type: Array,
@@ -127,25 +130,4 @@ const userSchema = mongoose.Schema(
   { timestamps: true },
 );
 
-userSchema.index(
-  { googleId: 1 },
-  { unique: true, partialFilterExpression: { googleId: { $type: 'string' } } },
-);
-userSchema.index(
-  { facebookId: 1 },
-  { unique: true, partialFilterExpression: { facebookId: { $type: 'string' } } },
-);
-userSchema.index(
-  { openidId: 1 },
-  { unique: true, partialFilterExpression: { openidId: { $type: 'string' } } },
-);
-userSchema.index(
-  { githubId: 1 },
-  { unique: true, partialFilterExpression: { githubId: { $type: 'string' } } },
-);
-userSchema.index(
-  { discordId: 1 },
-  { unique: true, partialFilterExpression: { discordId: { $type: 'string' } } },
-);
-
 module.exports = userSchema;
diff --git a/api/strategies/socialLogin.js b/api/strategies/socialLogin.js
index 4b900371d1..3602a5438a 100644
--- a/api/strategies/socialLogin.js
+++ b/api/strategies/socialLogin.js
@@ -3,6 +3,11 @@ const { isEnabled } = require('~/server/utils');
 const { findUser } = require('~/models');
 const { logger } = require('~/config');
 
+/**
+ * Returns a function that handles the social login flow for a given provider.
+ * @param {string} provider - The provider name (e.g. 'google', 'facebook').
+ * @param {Function} getProfileDetails - A function to extract user details from the provider profile.
+ */
 const socialLogin =
   (provider, getProfileDetails) => async (accessToken, refreshToken, idToken, profile, cb) => {
     try {
@@ -31,6 +36,8 @@ const socialLogin =
         });
         return cb(null, newUser);
       }
+
+      return cb(null, null);
     } catch (err) {
       logger.error(`[${provider}Login]`, err);
       return cb(err);