Pink screen flicking while waiting for auto lock screen working.

My iPhone16 using Teal color collection wallpaper for iPhone16 and set auto Lock Screen in 1 min. When I wait it countdown to auto Lock Screen working when pass 30 sec. The screen was dimming and have issues that only background not app icon turn in to pink screen flicking for 30 sec. Then auto lock after 1 min. And I rise to wake to background that flicking in pink color turn into normal. Anybody knows that happens from iOS18 / iPhone16 collection wallpaper is bug or my screen really got issues.