Hi there! I understand how concerning it must be not receiving messages from your grandkids on Messenger Kids. Let’s troubleshoot this together and see if we can get it sorted out.

1. Check Internet Connection: First, ensure that both your device and your grandkids' devices have a stable internet connection. If possible, try switching between Wi-Fi and mobile data.

2. Update the App: Make sure you have the latest version of Messenger Kids installed. Updates often contain fixes for known issues. You can check for updates in the Microsoft Store.

3. Clear Cache and Data: Sometimes, clearing the cache and data can resolve messaging issues. However, this step is generally more applicable to mobile devices than to where you're accessing it. Still, if you're using a dedicated app on a Windows device, you might have options in the app settings to clear cache.

4. Double-check Contacts: Ensure that your grandkids are still added as contacts. You can go into Messenger Kids and verify that their accounts are connected.

5. Restart the Device: A simple restart can often resolve unexpected glitches. So, go ahead and restart your device.

6. Notifications Settings: Make sure that notifications for Messenger Kids are enabled so that you are alerted when new messages come in.

If you've tried all these steps and are still having issues, let me know, and we can dig deeper into the problem or potentially reach out for further support. Are you satisfied with the solutions I provided so far?