Maybe it is the service you are using????
I heard some services don't work very well with Smart IPTV ............ but I don't have any SmarTVs to test - only dumb ones....LOL
I snipped this from one service:
Instructions
Find your TVs MAC address by opening app on your tv
Go to SmartTV page:
Code:
https://siptv.app/news/
Go to the top page menu and click "My List"
Find "Add external playlist links (URLs), with auto-update" about the middle of the page
Enter your MAC address of your TV and then paste your M3U list where it says "Link"
Choose country and enable list logos
Click "Add Link"
Go back to your TV and reload the SmartIPTV app.
Wish I had a SmarTV to test