iPhone XR take a second to go to sleep, instead of going out instantly I got my iPhone XR just days ago and just recently upgraded to IOS 14. Now, the problem I am facing is no way near crazy problematic. However, it is kinda concerning given it's a brand new phone. After updating to IOS 14, it seems like my iPhone is &quot;taking its time&quot; to go to sleep. Like initially, I'd press the power button and it would immediately go to sleep but now it actually takes a second to go out followed by the locking sound effect. I don't know if the problem is because of updating to IOS 14 or something else. I hope someone could help me figure this out.
The side button won’t immediately sleep your phone if iOS is waiting for a potential second press of the button. Features which enable a second press of the side button and thus delay sleep are:

Apple Pay, where double press of the side button opens the wallet to your cards.
Accessibility Shortcut (Settings → Accessibility), where triple press of the side button toggles your selected shortcut or opens a menu of your selected options.

Disabling these features will ensure a single press of the side button can only mean sleeping the device, therefore iOS won’t wait for a potential second press.