diff --git a/tracker/tracker/src/main/app/index.ts b/tracker/tracker/src/main/app/index.ts
index 9cbbbf5d5..36c42764d 100644
--- a/tracker/tracker/src/main/app/index.ts
+++ b/tracker/tracker/src/main/app/index.ts
@@ -1635,7 +1635,7 @@ export default class App {
   }
 
   flushBuffer = async (buffer: Message[]) => {
-    return new Promise((res) => {
+    return new Promise((res, reject) => {
       if (buffer.length === 0) {
         res(null);
         return;
@@ -1648,9 +1648,19 @@ export default class App {
         endIndex++;
       }
 
-      const messagesBatch = buffer.splice(0, endIndex);
-      this.postToWorker(messagesBatch);
-      res(null);
+      requestIdleCb(() => {
+        try {
+          const messagesBatch = buffer.splice(0, endIndex);
+
+          // Cast out the proxy object to a regular array.
+          this.postToWorker(messagesBatch.map(x => [...x]));
+
+          res(null);
+      } catch (e) {
+          this._debug('flushBuffer', e);
+          reject(e);
+      }
+      })
     })
   }