fix: 断线后点击重玩，退出按钮消失问题

assets/op_16/prefab/PlayerOffLineLayer/PlayerOffLineLayer.js

@@ -8,15 +8,17 @@ cc.Class({
         const BtnExit = cc.find('BtnFrame/BtnExit', this.node);
         BtnExit.on('click', ()=>{
             const middleLayer = cc.find('middleLayer');
-            if(middleLayer) {
-                cc.game.removePersistRootNode(middleLayer);
+            if (middleLayer) {
+              const middleLayerComponent = middleLayer.getComponent('middleLayer');
+              if (middleLayerComponent.onClickExitBtn) {
+                middleLayerComponent.onClickExitBtn();
               }
+            } else {
               cc.director.getScene().destroy();
               cc.audioEngine.stopAll();
               if (window.courseware) {
                 window.courseware.freeAllOcMethod();
               }
-
               var bundle = cc.assetManager.bundles.find((obj) => {
                 return obj.getSceneInfo('debug_shell');
               });
@@ -25,19 +27,25 @@ cc.Class({
               } else {
                 cc.director.loadScene("OXFORDCORE", null, null, (err, scene) => { });
               }
+            }
         });
         const BtnPlayAgain = cc.find('BtnFrame/BtnPlayAgain', this.node);
         BtnPlayAgain.on('click', ()=>{
+            const middleLayer = cc.find('middleLayer');
+            if (middleLayer) {
+              const middleLayerComponent = middleLayer.getComponent('MiddleLayer');
+              if (middleLayerComponent) {
+                middleLayerComponent.reloadBundle();
+              }
+            } else {
               const sceneName = cc.director.getScene().name;
               cc.director.getScene().destroy();
               cc.audioEngine.stopAll();
               if (window.courseware) {
                 window.courseware.freeAllOcMethod();
               }
-
-            cc.director.loadScene(sceneName, null, null, (err, scene) => {
-
-            });
+              cc.director.loadScene(sceneName, null, null, (err, scene) => { });
+            }
         });
     },
 });