It's not broken, and not harmful to your phone. To fix it just stop shaking your phone.
Hello @alsoJay ,
"This isn't a problem. It is just the lenses of the camera moving around when not being used. The lenses are stabilized with electromagnetism. When they aren't used, they will move around as there are no gears or mechanics to hold it into place."
Be sure to check your resolution on your post so other know the resolution for the same question they may have.
I'm happy im not the only person I phoned Samsung other day the guy I spoke to didn't even know any of this but after reading these comments I can now see when I open the camera app the rattle stops makes me feel a bit better now I know I'm not the only person I was ready to hand the phone back 😅
My phone didn't rattle until over a week of use and then I noticed the rattle every time I picked it up . If it didn't rattle for over a week then clearly it is possible for it not to rattle, right? Meaning, it is fixable and all the chat support specialists would tell me is that it is "normal". Normal does not mean it isn't a problem or a defect even. Normal just means it happens a lot which is cause for concern in a phone so expensive. Fix your phones Samsung or don't ship them.
I noticed that too, if seems to be a manufactory defeact all s20 ultras I seen do that same rattling noise. Like if something was loose or broken inside the cell phone.