Hello nedmachfx,
Thank you for using Apple Support Communities. We can offer some basic steps you can try to make sure that your iPhone is properly working. These steps could possibly sort out this issue with connecting to your TV. Follow these steps here:
1.) Restart your iPhone and your TV. This usually helps refresh things.
2.) Make sure that you're using the recommended Wi-Fi settings. This helps with performance and reliability.
Additional steps you might want to consider is checking for firmware updates that might be available for your TV. Also, if you have any pending updates for your iPhone, it would be a good idea to install them. Keeping your device fully updated can help resolve various issues. Just in case, this resource can guide you through the update process: Update your iPhone or iPad - Apple Support
1.) Back up your device using iCloud or your computer.
2.) Plug your device into power and connect to the internet with Wi-Fi.
3.) Go to Settings > General, then tap Software Update.
4.) If you see more than one software update option available, choose the one that you want to install.
5.) Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.
We hope these steps are helpful. Thank you for using Apple Support Communities. Cheers.