Hi! I understand your VIVOSUN app on your iPhone running iOS 18.6 is not connecting to Wi-Fi after an update. Let's get this sorted out together.

To start, could you tell me:
- Is it the app itself that won't connect to your home Wi-Fi, or is the issue that the app can't connect to your VIVOSUN device's controller?
- Are other apps on your phone able to use Wi-Fi without issues?
- Have you tried basic steps like restarting your iPhone or toggling Wi-Fi off and on?

Based on what you shared so far, here’s a step-by-step guide to troubleshoot the VIVOSUN app Wi-Fi connectivity issue after an update:

1. Check Wi-Fi Network Band:
Make sure your Wi-Fi network is running on the 2.4 GHz band, not just 5 GHz, as VIVOSUN devices often require 2.4 GHz to connect properly.

2. Restart Devices:
Power cycle your Wi-Fi router, the VIVOSUN GrowHub controller (if you use one), and your iPhone. Sometimes a fresh reboot can resolve connectivity glitches.

3. Forget and Rejoin Network:
On your iPhone, go to Settings > Wi-Fi, find your Wi-Fi network, tap the info icon (i), and choose Forget This Network. Then reconnect by entering your password again.

4. Check App Permissions:
Ensure the VIVOSUN app has permission to access your local network and Wi-Fi. In iOS, go to Settings > VIVOSUN and verify that Wi-Fi and Local Network permissions are enabled.

5. Update the App and Firmware:
Check if there is a newer version of the app or controller firmware. Inside the app, navigate to Settings > Firmware Update to ensure your device firmware is current.

6. Reset GrowHub Controller (if applicable):
If your GrowHub controller is involved, try performing a factory reset by holding the reset button as described in its manual, then attempt to pair again with the app over Wi-Fi.

7. Network Interference or Router Settings:
Sometimes router firewall or security settings block the connection. Make sure your router allows the necessary ports and the device isn't being blocked by MAC address filtering.

If these steps don't resolve the problem, please let me know which step you tried and what happened. Also, if you see any error messages in the app, share those with me. That will help me guide you further!

Are you satisfied with this first set of suggestions? If not, we can dig deeper.