Hello, are you using the Smart Things app to connect the TV and the iPhone?
If you are, can you instead try to connect both with bluetooth? Through some research on the internet, I have also found that pictures that have a resolution greater than 1600x900 have some issues uploading to the Frame TV. If so, you can try resizing those photos through 3rd party apps to try to fix it.
Let me know how it goes! Thanks
I've found the connection of the SmartThings app to the TV to be hit-and-miss. Here are a couple of things I try with the iPhone version of the app when the connection isn't working:
1. Force-close the SmartThings app and restart it.
2. Give the app time to load before trying to use it.
When opening the app, wait 5-10 seconds until the status of your TV is refreshed before tapping on it. After opening up the control screen for your TV, wait another 5-10 seconds until the "Sources & Apps" and "Art Mode" sections populate. Tap the three dots in the upper right corner to bring up the "Art" menu. If the option for "Art Mode settings" is active and not grayed-out, you should be good to go. If not, try the next option.
3. Reconnect the app to your TV
Turn on the TV and switch to a connected device like a cable/satellite box or blu-ray player (it may work on a streaming service too). Launch the app and approve the connection on the TV screen with the Smart Remote if an approval request is displayed.