Switching between wallpapers on a locked screen stopped working

Hello leehpo,

Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with your touchscreen after the update. Have you tried restarting your iPhone? This simple step resolves a multitude of issues: Restart your iPhone  Restart your iPhone - Apple Support

If not, try the remaining steps listed here to see if they resolve the issue: If the screen isn't working on your iPhone or iPad If the screen isn't working on your iPhone or iPad - Apple Support

"You might need to set up service for your device.

If your screen is too sensitive or responds intermittently to touch

1. Restart your iPhone or iPad.
2. Make sure that your screen is clean and free of any debris or water.
3. Disconnect any Lightning or USB-C accessories. If your screen works after removing an accessory, try using a different outlet, cable, or charger.
4. Remove any cases or screen protectors.

Contact Apple Support

If your screen still isn't working, you might need to set up service for your device. Contact Apple Support."

We hope this helps.

Cheers!