Zf makes clunking sound when turned off.

Yesterday I finally bought my first mirrorless camera - a Nikon Zf with the 40mm kit lens. I also got the FTZII so I can use some of my F Mount lenses. I am still setting up the camera and going through all the customization options, but it seems like a very nice piece of gear.

I noticed that when the camera is turned off, if I tilt it from side to side, it makes a subtle clunking sound, and it feels like something is moving inside the body. I suspect this is normal, and may be related to the IBIS system, but thought I'd confirm here with people who have more experience with mirrorless cameras, or maybe particularly with the Zf. This sound and movement is not present when the camera is powered on. Any ideas? Should I be concerned? 

Correction, the sound can be heard and movement felt whenever the LCD screen is off, regardless of whether the camera is powered on or not. 

It's the sensor which moves freely when the power is off or when LV is not active. In other models such as the Z8, the sensor is locked in position. I believe Nikon changed the ibis design to squeeze it into the thinner body of the Zf.

Both my Df and Zf, the latter, so far comparatively little used, are virtually silent. Just the tiniest little click on the ZF, quieter by far the the shutter sound.

10 hours ago, ilkka_nissila said:

It's the sensor which moves freely when the power is off or when LV is not active. In other models such as the Z8, the sensor is locked in position. I believe Nikon changed the ibis design to squeeze it into the thinner body of the Zf.

Makes sense. I didn't think they would just let the sensor rattle around when the camera is not in use, but I guess they made sure that a reasonable amount of shock that the camera may experience will not damage anything inside.

10 hours ago, Sandy Vongries said:

Both my Df and Zf, the latter, so far comparatively little used, are virtually silent. Just the tiniest little click on the ZF, quieter by far the the shutter sound.

I just realized I wrote Df in the subject line when I meant to write Zf, sorry about that. It took a while for me to get used to Nikon cameras starting with D instead of F, now it will be a similar process to get used to the Z prefix. I assume the Df does not make the same noise that I am referring to. 

I just updated the thread subject, and it says Zf now.

I have four different Nikon Z bodies but have no Zf. I just checked all of them (Z6, Z6ii, Z8, and Z9), and none of them makes any sound when I rotate them from landscape to portrait, but I have removed all lenses and FTZ adapters, and I also hold onto those strap lugs to make sure that they don't make any sound.