Black spot on iphone 13 pro max camera screen

Hi, I started having the exact same issue as you on my phone when I use the 3x lens, after some research its apparently dust stuck in the actual camera, how it got there I have no idea, its a known issue and is covered under apples limited warranty so they should replace the camera or the handset. I have an appointment booked on Tuesday lets see how it goes.

Update - took my phone in today and needed a rear and front camera replacement (black spot on actual camera lens) and a screen replacement, they couldn’t fix so replaced the phone for a brand new handset. I urge anybody if you are having bad picture quality and fuzzy pictures with zero sharpness to take your phone to an apple store and get it replaced under the warranty. The new handset I got works perfectly now and pictures look much better than before.

Irrespective of anyone else having this rare defect, which it looks like, you should arrange a repair under warranty.

https://support.apple.com/iphone/repair/service

or: contact Apple Support 

Thats great, glad I could help.