EOS R6 Mark II shutter button triggers odd sound with EF lenses, RF OK

[Jenga]

Hi! First timer here!  I have an R6M2 and I use both RF and EF lenses.  I have the ring adapter. Some of my photography requires that I use the silent shutter.  I haven't had any issues with the EF lenses until this past weekend.  It makes an odd sound that i can't explain (electronic buzz/click maybe?) when I press the shutter button.  It's not the AF and I don't have IS on my lenses.  It is all 3 of my EF lenses so it's not the lens itself.  It takes the photo as normal. I've taken it off, put it back in, cleaned the contacts,  etc.  Everything i could think of. My RF lens is fine.  I'm kind of in a panic as I need this lens for a job this weekend.  I'm hoping someone here can help.  I have a video of the sound it's making but it doesn't look like I can upload it here. Gah. 

[kvbarkley]

Could it be IBIS? You should be able to turn that off in the menus.

[Jenga]

Nope lol. I tried that too.  It's happening with my 70-200, 50 and 24 EF lenses.  When I put my ear up to it, it's coming from the camera body for sure and when pressing shutter button.  I'm perplexed  

[Jenga]

Here is a link to a video I took.  The sound is when i press shutter button.

https://drive.google.com/file/d/1jA1SODuNYF8d3yk3ntr8eK2K1BDHWO3s/view?usp=sharing

[kvbarkley]

Other than IBIS, there is nothing in the camera that can vibrate.

[Jenga]

It is not a vibration.  It is a sound when i press the shutter button and the shutter is on silent.  

[Jenga]

Here is a link to a video I took. The sound is when i press shutter button.

https://drive.google.com/file/d/1jA1SODuNYF8d3yk3ntr8eK2K1BDHWO3s/view?usp=sharing 

[Peter]

The aperture?

[Jenga]

Nope. It only happens when i press the shutter button and it takes the photo...and it's only with my EF lenses on the adapter. 

[kvbarkley]

Unless the mirrorless operate different than DSLR's, the aperture is wide open during focusing and stops down only to take the image.

You can put the camera in AV mode at the widest aperture to see if that is the noise, alternately, you can look into the lens, set a small aperture, and see if the noise correlates with the aperture.