The phone will not open even after tapping on the back three times
I will put the phone in the holster. I go to use the phone, and it will not wake up even after tapping on the back.
Tap the power button to wake the iPhone, if the screen tap function is disabled.
What the back tap does varies by phone model (iOS 14 and later), and settings.
Tap the back of iPhone to perform actions or shortcuts - Apple Support
