It's been 2 days since my iphone 12 (on iOS 16) started to randomly crash. It randomly starts being laggy or freezing, then it shuts down on its own and then restarts a few moments later. It does this regardless of the battery percentage, of whether I'm using it or not, of whether an app's open or not.

I tried to make more room by deleting photos, videos, and apps. Storage is currently at 117 GB used out of 128 GB. I read somewhere that it must be a RAM problem but I don't understand how that could be since I close all the apps when I don't use them.

I've been attempting to update the software since there's an available iOS 16.3.1 but it kept failing. I can't get past the "Preparing update" phase. I'm not sure if it's the network that's problematic or if it's one of the issues it's causing.

Does anyone know what else I can do? These random crashes are really disrupting my daily activities since I rely so much on my phone to get a lot of things done. Thank you.