IOS 18.3 NOT SHOWING THE PUSH UP NOTIFICATION

Until three days ago my cell phone was working as it was supposed to work, one day I noticed that my device (15 pro Max) started to have a certain delay in sending me notifications when it is locked, that is, if I have the cell phone in my hand, with the screen active it shows the PUSH UP notification right away, but if I lock the phone for 10 minutes, the messages that are sent to me take up to 20 minutes or more for the notification to appear on the locked screen, I have already searched the entire internet, including the Apple community itself and all the solutions such as, resetting network preferences, resetting all settings, RESETTING THE PHONE without putting my old account, activating all notifications, that is, everything that could be done was done, I just think it is disrespectful to the consumer to pay a lot for a device that should be PRO and aven to ALL other costumers have a simple problem with the cell phone forgetting to send the notification, APPLE, FIX THIS