Hi there! I see you're having trouble connecting to the Texas Health MyChart app on your iPhone running iOS 18.5. Let's try to get this sorted out together.

Could you please share a bit more about what exactly happens when you try to connect? For example, do you get any error messages, does the app freeze, or does it just fail to load? Also, are you trying to log in, or is the problem happening elsewhere in the app?

In the meantime, here are some initial steps we can try to fix common connection issues with MyChart on iOS:

1. Check your internet connection: Ensure you're connected to Wi-Fi or cellular data and that the connection is working by visiting any website in Safari.

2. Enable cookies: Sometimes, the app needs cookies enabled to communicate properly. On your iPhone, go to Settings > Safari and make sure "Block All Cookies" is off.

3. Restart the app: Fully close the MyChart app by swiping up from the bottom and swiping the app off the screen, then reopen it.

4. Restart your phone: Sometimes, a quick reboot can clear any temporary glitches.

5. Update the app: Open the App Store, tap your profile icon, and see if there’s an update available for Texas Health MyChart. If so, install it.

6. Allow necessary permissions: Go to Settings > MyChart and ensure permissions like location, cellular data, and background app refresh are enabled.

If you've tried these already or if the issue persists with an error message, let me know what you see, and we can dig deeper. Sometimes, connection errors may be related to server issues or account mismatches, too.

Also, if you get a message like "Please enable cookies to log in to MyChart," that specifically points to Safari settings needing adjustment.

Would you be able to try these and tell me what happens? I’m here to help you through the next steps!