Hi! I understand your SmartLife app linked to Google Home has stopped syncing new devices. Let's figure this out together.

To get started, could you please tell me:
- Have you recently changed your Google Account password or any security settings?
- Did you add any new devices to the SmartLife app that are not showing up in Google Home?
- Have you tried any steps so far to fix this? If yes, what have you tried?

Meanwhile, here are some common steps that often help resolve syncing issues:

1. Refresh the sync manually with Google Assistant: Try saying “Hey Google, sync my devices." This prompts Google Home to re-check for any new devices linked to your SmartLife account.

2. Re-link SmartLife account in Google Home:
- Open the Google Home app on your Mac via browser or via your phone.
- Go to “Settings” > “Works with Google” or “Linked services.”
- Find SmartLife, unlink it.
- Then, link SmartLife again by logging in and authorizing access.

3. Check your Google Account’s linked apps permissions:
- On your Mac, open a Chrome browser and go to your Google Account’s security settings.
- Scroll to “Third-party apps with account access” and make sure SmartLife is still authorized.

4. Device naming and setup in SmartLife:
- Make sure new devices are properly added and named in the SmartLife app first. Sometimes Google Home doesn’t sync devices if they are unnamed or not fully configured.

5. Network and Router:
- If you recently changed routers or network settings, ensure that your Mac and SmartLife devices are on the same Wi-Fi network and that any firewall is not blocking Google Home or SmartLife services.

If you've already tried unlinking and relinking or syncing commands, let me know. I can guide you through more advanced troubleshooting or we'll check if there’s a known outage affecting syncing between SmartLife and Google Home.

How does that sound? Would you like me to help you with any of these steps right now?