My iPhone 13's screen stays on when a notification arrives

Since Friday I realized when a notification arrives, or I turn on the device to see the time, then if I don’t press again the power button it won’t turn off. At first I thought it wasn’t that important but tonight I woke up twice and saw the mobile was with the screen on, since I don’t know when, and obviously my battery ran from 90 to 67. I’ve already changed the display settings and the auto-lock is 30 seconds, but it still does the same.

[Re-Titled by Moderator]