I just went to fly my P3 Advanced yesterday wanting to do some experimentation with the 2.7k video capabilities and for the life of me can NOT figure out where they went!
While everything is booted up and running (but props not engaged and not flying) I go into the camera settings menu, hit the video tab and my ONLY choices are 1080p (with various frame rates) and 720p (also with it's corrisponding frame rates). I'm quite sure I had the 2.7k option after the last (and latest) update (v1.8.80) but never tried using it until yesterday when I discovered that it is no longer available! Anyone else having this issue or am I just missing something???

Search for it, I've seen others mention this.  One person said to delete app and reinstall.  But I'd search first as others probably have the answer.

My advanced was doing the same thing, except when I first bought it.  2.7K was not an option on my Ipad, however it was on my Iphone.  I deleted the app on my Ipad and reinstalled, this solved the issue.

Same here.  Deleted and reinstalled DJI GO and 2.7 reappeared.  Thanks to jermc10.

Thank you all for the responses. I checked out some older posts on the same subject (thanks tytlyf) and after backing up my data to the cloud, I uninstalled and then reinstalled the app on my iPad and it seems that the 2.7k capabilities have been restored! I also noticed that the signal between controller and craft is much more stable as well! I kept getting signal dropouts even thought the aircraft was hovering 4ft off the ground directly in front of me! I'm a happy pilot again!!!