Fix serialization to dictionaries

src/utils/saveload.ts

@@ -60,7 +60,7 @@ export function GetCircularReplacer(): (key: any, value: object | Map<string, an
     if (key === 'parent') {
       return;
     }
-  
+
     if (key === 'containers') {
       return Array.from((value as Map<string, any>).entries());
     }
@@ -83,6 +83,14 @@ export function GetCircularReplacerKeepDataStructure(): (key: any, value: object
       return;
     }
 
+    if (key === 'containers') {
+      return Object.fromEntries(value as Map<string, any>);
+    }
+
+    if (key === 'symbols') {
+      return Object.fromEntries((value as Map<string, any>));
+    }
+
     return value;
   };
 }