Fix (#9648)

v2rayN/ServiceLib/Models/CoreConfigs/V2rayConfig.cs

@@ -289,16 +289,7 @@ public class BalancersStrategySettings4Ray
 {
     public int? expected { get; set; }
     public string? maxRTT { get; set; }
-    public float? tolerance { get; set; }
+    public double? tolerance { get; set; }
-    public List<string>? baselines { get; set; }
-    public List<BalancersStrategySettingsCosts4Ray>? costs { get; set; }
-}
-
-public class BalancersStrategySettingsCosts4Ray
-{
-    public bool? regexp { get; set; }
-    public string? match { get; set; }
-    public float? value { get; set; }
 }
 
 public class Observatory4Ray

v2rayN/ServiceLib/Services/CoreConfig/V2ray/V2rayBalancerService.cs

@@ -89,22 +89,25 @@ public partial class CoreConfigV2rayService
             EMultipleLoad.RoundRobin => "roundRobin",
             EMultipleLoad.LeastPing => "leastPing",
             EMultipleLoad.LeastLoad => "leastLoad",
+            EMultipleLoad.Fallback => "leastLoad",
             _ => "roundRobin",
         };
         var balancerTag = $"{selector}{Global.BalancerTagSuffix}";
         var balancer = new BalancersItem4Ray
         {
             selector = [selector],
-            strategy = new()
+            strategy = strategyType == "leastLoad" ? new()
             {
                 type = strategyType,
                 settings = new()
                 {
                     expected = 1,
+                    tolerance = multipleLoad == EMultipleLoad.Fallback ? 0.2 : null,
+                    maxRTT = multipleLoad == EMultipleLoad.Fallback ? "5000ms" : null,
                 },
-            },
+            } : null,
             tag = balancerTag,
-            fallbackTag = multipleLoad == EMultipleLoad.Fallback ? Global.DirectTag : null,
+            fallbackTag = _coreConfig.outbounds?.FirstOrDefault(o => o.tag.StartsWith(selector))?.tag,
         };
         _coreConfig.routing.balancers ??= [];
         _coreConfig.routing.balancers.Add(balancer);