low battery notification for 10/20% is not showing up anymore after upgrading to the 15 pro max

i had an iphone 14 with this feature still working, however after upgrading to the iphone 15 pro max 9 days ago the notifications have stopped appearing. in just a single week my phone has already died on me twice without me even knowing that it was at low battery levels. i have heard people complain about this feature being intrusive and interrupting what you are doing, but that is the reason why it is so usefull for someone like me who never remembers to check my battery life. if this is a bug/problem with my phone. then how do i fix it, and if it is an intended feature how do i get back the notifications in the same way that they used to be.