Hi! I see you're having trouble loading the full screen weather video on your iPhone's WeatherNation app, while the video works fine on the initial screen. Let's dig into this together.

Sometimes, this kind of issue can happen due to temporary glitches, outdated app versions, or caching problems. Here's what I'd suggest stepping through:

1. Close and Restart the App
Fully close the WeatherNation app on your iPhone by swiping it away from the app switcher, then reopen it and try the full screen video again.

2. Check for App Updates
Go to the App Store and check if there is an update available for WeatherNation. Developers often fix video playback bugs in new updates, so ensuring you have the latest version is important.

3. Restart Your iPhone
A simple device restart can sometimes clear up any small glitches affecting video playback.

4. Check Network Connection
Make sure your iPhone has a strong and stable Wi-Fi or cellular connection. Video streaming requires good bandwidth, and partial loading can happen if the connection is spotty.

5. Clear Cache / Reinstall App
Since iOS doesn't allow direct cache clearing, you can delete the WeatherNation app from your iPhone and reinstall it fresh from the App Store. This can eliminate corrupted data that might be causing issues with full screen video.

6. Check iOS Version Compatibility
You mentioned your iPhone is running iOS 18_6_2 (which I interpret as iOS 18.6.2 or a close version). Confirm the WeatherNation app supports this iOS version. Usually, apps do, but it's worth checking the app description on the App Store or developer site.

If after trying these you're still stuck with the full screen video not loading, let me know if any error messages pop up or if the video just spins without loading. Also, I'd be happy to check on any current known issues with WeatherNation's full screen video for iOS specifically.

Would you like me to guide you through any of these steps one at a time?