[Samsung Galaxy Note 9 Questions & Answers] mongler:
I have this issue as well (unlocked model).

I had a similar issue on my note 5 (that model also produced a "buzzing" noise as the OIS mechanical, possibly MEMS based, system itself stabilized).

My Note 9 does this as well, consistent with the behavior in this thread and reported elsewhere on the internet . There are plenty of Youtube videos that accurately reproduce the problem.

It seems to be a common problem, although I admit I did not notice it when I first started using my phone.

I admit, the first time I noticed it was after a moderate drop. I have a rugged case (a Supcase, one of only a handful of rugged Note 9 cases that come with a built in screen protector).

I dropped the phone from 2~3 feet, and the phone landed on or near the corner, meaning it translated a lot of the impulse of the impact into the phone and the case's chassis.

That was when I first noticed the rattling. I picked up the phone and shook it to hear if there was anything wrong and noticed the rattling. It may be that this was simply the first time I actually noticed the noise and that it was always there, but its also possible that the impact of that fall caused some component of the OIS system to come loose or break.

It would be nice to hear from Samsung about this.

To reiterate:

i noticed this on my super old Note 5. Same exact sort of behavior with the camera, although that one produced the known buzzing/hissing noise associated with the OIS system, itself, stabilizing (also a visible distortion in the image displayed as the system came into balance).

My suspicion is that this is probably similar to the problem with the Note 5. Annoying. Odd for a flagship. Scary. Especially considering the price. AND.... critically.... possibly something that may become worse over time.

No obvious functionality issues.

One thing that might help would be an app or service that will provide a more thorough diagnostic of the camera sensor. Whatever that entails. Running all systems through their range of calibration and functionality to detect any problems.

Given the IP68 rating, I would be surprised if a drop from 2-3 feet with a known quantity rugged case would not be a warranty issue if the camera were damaged in some way.

my biggest concern is that if the, presumably OIS system, is allowed to wobble around to an extent that *sounds* like movement on the order of ~0.5-1.0 mm (which is miles of movement in this type of application), will this result in long term damage. If, every time I take a step, the sensor is wobbling back and forth.... 10s or hundreds of thousands of times... up and down every time I jump in and out of my car (I literally jump, its a big vehicle).... will these things reduce the lifespan of the camera as a result of this "looseness"?

On a side note if you did not buy your Note 9 from Samsung.com directly you cannot ever forever sign up for Samsung Premium care.

They absolutely will not, under any circumstances, allow you to sign up for their premium insurance plan, even if you purchased the device from Att or Verizon or T-mobile.... Even if you bought it yesterday. Even if you go to Best Buy and let someone look at the pone and verify that its not damaged.

no possibility. So its 100% Asurion and the warranty.

If you have ever tried to replace a Note with Asurion, you know that they typically do not provide direct replacements. Instead they will provide you with the newest top-tier S-phone. Either because they don't ever have enough refurb Note devices, or because the Note is too expensive, wholesale. Even Samsung has had issues with Note replacements through warranty or insurance.