diff --git a/src/Ocelot/Configuration/AuthenticationOptions.cs b/src/Ocelot/Configuration/AuthenticationOptions.cs
index 0021a8034..85ad3bba9 100644
--- a/src/Ocelot/Configuration/AuthenticationOptions.cs
+++ b/src/Ocelot/Configuration/AuthenticationOptions.cs
@@ -23,8 +23,7 @@ public AuthenticationOptions(List<string> allowedScopes, string authenticationPr
         public AuthenticationOptions(List<string> allowedScopes, string[] authenticationProviderKeys, List<string> requiredRole, string scopeKey, string roleKey, string policyName)
         {
             AllowedScopes = allowedScopes;
-            AuthenticationProviderKey = string.Empty;
-            AuthenticationProviderKeys = authenticationProviderKeys ?? Array.Empty<string>();
+            BuildAuthenticationProviderKeys(null, authenticationProviderKeys);
             PolicyName = policyName;
             RequiredRole = requiredRole;
             ScopeKey = scopeKey;
@@ -41,6 +40,8 @@ private void BuildAuthenticationProviderKeys(string legacyKey, string[] keys)
             keys ??= Array.Empty<string>();
             if (string.IsNullOrEmpty(legacyKey))
             {
+                AuthenticationProviderKeys = keys;
+                AuthenticationProviderKey = string.Empty;
                 return;
             }
 
diff --git a/src/Ocelot/Configuration/Creator/AuthenticationOptionsCreator.cs b/src/Ocelot/Configuration/Creator/AuthenticationOptionsCreator.cs
index 86d0ea43c..75f9a79c3 100644
--- a/src/Ocelot/Configuration/Creator/AuthenticationOptionsCreator.cs
+++ b/src/Ocelot/Configuration/Creator/AuthenticationOptionsCreator.cs
@@ -4,5 +4,5 @@ namespace Ocelot.Configuration.Creator;
 
 public class AuthenticationOptionsCreator : IAuthenticationOptionsCreator
 {
-    public AuthenticationOptions Create(FileRoute route) => new(route.AuthenticationOptions);
+    public AuthenticationOptions Create(FileRoute route) => new(route?.AuthenticationOptions ?? new());
 }
diff --git a/src/Ocelot/Configuration/File/FileAuthenticationOptions.cs b/src/Ocelot/Configuration/File/FileAuthenticationOptions.cs
index ad1ed648a..6d972092d 100644
--- a/src/Ocelot/Configuration/File/FileAuthenticationOptions.cs
+++ b/src/Ocelot/Configuration/File/FileAuthenticationOptions.cs
@@ -30,28 +30,11 @@ public FileAuthenticationOptions(FileAuthenticationOptions from)
         public override string ToString() => new StringBuilder()
             .Append($"{nameof(AuthenticationProviderKey)}:'{AuthenticationProviderKey}',")
             .Append($"{nameof(AuthenticationProviderKeys)}:[{string.Join(',', AuthenticationProviderKeys.Select(x => $"'{x}'"))}],")
-            .Append($"{nameof(AllowedScopes)}:[{string.Join(',', AllowedScopes.Select(x => $"'{x}'"))}]")
+            .Append($"{nameof(AllowedScopes)}:[{string.Join(',', AllowedScopes.Select(x => $"'{x}'"))}],")
+            .Append($"{nameof(RequiredRole)}:[").AppendJoin(',', RequiredRole).Append("],")
+            .Append($"{nameof(ScopeKey)}:[").AppendJoin(',', ScopeKey).Append("],")
+            .Append($"{nameof(RoleKey)}:[").AppendJoin(',', RoleKey).Append("],")
+            .Append($"{nameof(PolicyName)}:[").AppendJoin(',', PolicyName).Append(']')
             .ToString();
-
-        public string ToString2()
-        {
-            var sb = new StringBuilder();
-            sb.Append($"{nameof(AuthenticationProviderKey)}:{AuthenticationProviderKey},{nameof(AllowedScopes)}:[");
-            sb.AppendJoin(',', AllowedScopes);
-            sb.Append("]");
-            sb.Append($",{nameof(RequiredRole)}:[");
-            sb.AppendJoin(',', RequiredRole);
-            sb.Append("]");
-            sb.Append($",{nameof(ScopeKey)}:[");
-            sb.AppendJoin(',', ScopeKey);
-            sb.Append("]");
-            sb.Append($",{nameof(RoleKey)}:[");
-            sb.AppendJoin(',', RoleKey);
-            sb.Append("]");
-            sb.Append($",{nameof(PolicyName)}:[");
-            sb.AppendJoin(',', PolicyName);
-            sb.Append("]");
-            return sb.ToString();
-        }
     }
 }
diff --git a/test/Ocelot.UnitTests/Configuration/AuthenticationOptionsCreatorTests.cs b/test/Ocelot.UnitTests/Configuration/AuthenticationOptionsCreatorTests.cs
index d0e8d599e..d9cd320fa 100644
--- a/test/Ocelot.UnitTests/Configuration/AuthenticationOptionsCreatorTests.cs
+++ b/test/Ocelot.UnitTests/Configuration/AuthenticationOptionsCreatorTests.cs
@@ -46,7 +46,7 @@ public void Create_OptionsObjIsNotNull_CreatedSuccessfully(bool isAuthentication
         // Arrange
         string authenticationProviderKey = !isAuthenticationProviderKeys ? "Test" : null;
         string[] authenticationProviderKeys = isAuthenticationProviderKeys ?
-            new string[] { "Test #1", "Test #2" } : null;
+            new string[] { "Test #1", "Test #2" } : Array.Empty<string>();
         var fileRoute = new FileRoute()
         {
             AuthenticationOptions = new FileAuthenticationOptions
@@ -56,11 +56,13 @@ public void Create_OptionsObjIsNotNull_CreatedSuccessfully(bool isAuthentication
                 AuthenticationProviderKeys = authenticationProviderKeys,
             },
         };
-        var expected = new AuthenticationOptionsBuilder()
-            .WithAllowedScopes(fileRoute.AuthenticationOptions?.AllowedScopes)
-            .WithAuthenticationProviderKey(authenticationProviderKey)
-            .WithAuthenticationProviderKeys(authenticationProviderKeys)
-            .Build();
+
+        var b = new AuthenticationOptionsBuilder()
+            .WithAllowedScopes(fileRoute.AuthenticationOptions?.AllowedScopes);
+        b = isAuthenticationProviderKeys
+            ? b.WithAuthenticationProviderKeys(authenticationProviderKeys)
+            : b.WithAuthenticationProviderKey(authenticationProviderKey);
+        var expected = b.Build();
 
         // Act
         var actual = _authOptionsCreator.Create(fileRoute);
diff --git a/test/Ocelot.UnitTests/Configuration/Validation/FileConfigurationFluentValidatorTests.cs b/test/Ocelot.UnitTests/Configuration/Validation/FileConfigurationFluentValidatorTests.cs
index 7fe8729da..f619ffaa6 100644
--- a/test/Ocelot.UnitTests/Configuration/Validation/FileConfigurationFluentValidatorTests.cs
+++ b/test/Ocelot.UnitTests/Configuration/Validation/FileConfigurationFluentValidatorTests.cs
@@ -432,8 +432,7 @@ public void Configuration_is_invalid_with_invalid_authentication_provider()
             this.Given(x => x.GivenAConfiguration(route))
                 .When(x => x.WhenIValidateTheConfiguration())
                 .Then(x => x.ThenTheResultIsNotValid())
-                .And(x => x.ThenTheErrorMessageAtPositionIs(0, "Authentication Options AuthenticationProviderKey:'Test',AuthenticationProviderKeys:['Test #1','Test #2'],AllowedScopes:[] is unsupported authentication provider"))
-                .And(x => x.ThenTheErrorMessageAtPositionIs(0, "Authentication Options AuthenticationProviderKey:Test,AllowedScopes:[],RequiredRole:[],ScopeKey:[],RoleKey:[],PolicyName:[] is unsupported authentication provider"))
+                .And(x => x.ThenTheErrorMessageAtPositionIs(0, "Authentication Options AuthenticationProviderKey:'Test',AuthenticationProviderKeys:['Test #1','Test #2'],AllowedScopes:[],RequiredRole:[],ScopeKey:[],RoleKey:[],PolicyName:[] is unsupported authentication provider"))
                 .BDDfy();
         }
 
diff --git a/test/Ocelot.UnitTests/Configuration/Validation/RouteFluentValidatorTests.cs b/test/Ocelot.UnitTests/Configuration/Validation/RouteFluentValidatorTests.cs
index 12ea69eee..a15123e41 100644
--- a/test/Ocelot.UnitTests/Configuration/Validation/RouteFluentValidatorTests.cs
+++ b/test/Ocelot.UnitTests/Configuration/Validation/RouteFluentValidatorTests.cs
@@ -234,8 +234,7 @@ public void should_not_be_valid_if_specified_authentication_provider_isnt_regist
             this.Given(_ => GivenThe(fileRoute))
                 .When(_ => WhenIValidate())
                 .Then(_ => ThenTheResultIsInvalid())
-                .And(_ => ThenTheErrorsContains($"Authentication Options AuthenticationProviderKey:'JwtLads',AuthenticationProviderKeys:[],AllowedScopes:[] is unsupported authentication provider"))
-                .And(_ => ThenTheErrorsContains($"Authentication Options AuthenticationProviderKey:JwtLads,AllowedScopes:[],RequiredRole:[],ScopeKey:[],RoleKey:[],PolicyName:[] is unsupported authentication provider"))
+                .And(_ => ThenTheErrorsContains($"Authentication Options AuthenticationProviderKey:'JwtLads',AuthenticationProviderKeys:[],AllowedScopes:[],RequiredRole:[],ScopeKey:[],RoleKey:[],PolicyName:[] is unsupported authentication provider"))
                 .BDDfy();
         }