My iPhone keeps freezing when I receive notifications, it's been happening for quite a few years already. I thought it was something to do with my phone being too full because this is when the problem started. It got too full it wouldn't boot for some time.

I've contacted Apple support several times but they aren't able to give a solution. They said there was nothing wrong with the storage. They suggested wiping my phone settings which I did which made no difference, was a major pain setting everything back up. They said to keep my iOS updated which I always do and hope it fixes the issue.

I've even upgraded to a newer model, once the data was transferred across the new iPhone also had the same problem. I thought it was a hardware issue before.

The freeze lasts for about a second and it doesn't affect every app, Youtube is always affected so its annoying when I am trying to watch a video and get several notifications. Both the video and sound freeze. It doesn't seem to freeze games though.

About two years later the older iPhone stopped freezing and is working normally. I don't know why it's okay all of a sudden yet my main iPhone isn't. Both iPhones have plenty of space now, the older one has less than the newer one.