@Anniebell33: I'm sorry to hear that you're experiencing this issue. Please can you try pressing the Volume Down and Power buttons together for around 10 seconds until the phone restarts. Don't worry, this won't affect your personal data or settings. Following the restart, head to Settings > Device care > Optimise now, followed by Memory > Clean now. Following these steps, try accessing Smart Select via the Edge Panel Handle to see if the problem persists. If it does, are you still able to take a screenshot by pressing the Volume Down and Power buttons together for a second until you see the edges of the screen flash?