EOS R5: Somehow all my photos got erased

[Merbl]

I tried to restore default settings in my camera as somehow the ISO got stuck on 12800 in manual mode despite me not setting it. Then I realized after the reseting to default, all my images got erased but read that is not suppose to happen as the memory card shkuldn't be affected, and lastly yesterday, when I switched batteries, I realized some pictures were not saved. Not sure what is happening. Very disappointing that all of this is happening with a new (refurbished) camera and I was wondering if anyone had similar expereinces and can share insights. Thanks!

[shadowsports]

Greetings,

Myself and others will try to help with plausible explanations how you may have gotten to this point.  

Performing a settings reset Main and/or Custom does not erase images from storage media.  This is a very deliberate action.  

Resetting the camera could make changes to custom file or naming conventions if used, but this would not delete files.  This action could keep new files from being saved correctly to media, until the card was formatted.  However, this would only occur if custom conventions were being used.  

The condition of the body new versus refurbished would not have any effect on this.  

Battery changes also does not cause data loss.  The exception would be if the camera completely died while images in the buffer were not written to storage media before complete loss of power.  

Hopefully others can add their comments.