Sharepoint Thumbmail not diplaying - Reserved

It's wild that MSOFT hasn't fixed this yet. Here's the formatting I used to overcome this without nuking the attachments ability. I used an if statement to determine whether the image column has the "Reserved" string. Of course, replacing "siteurl", "subsite", and "ListName" in the URL string.

{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
  "elmType": "div",
  "children": [
    {
      "elmType": "img",
      "attributes": {
        "src": "=if(indexOf(@currentField.fileName, 'Reserved' ) == 0,'https://siteurl.sharepoint.com/sites/subsite/Lists/ListName/Attachments/'+[$ID]+'/'+@currentField.fileName, @currentField.serverRelativeUrl"
      },
      "style": {
        "position": "relative",
        "top": "50%",
        "left": "10%",
        "margin-top": "10px",
        "width": "200px"
      }
    }
  ]
}

I faced the same issue, but if you go to List Settings -> Advanced Setting -> Attachment and disable Attachments, then when reuploading the images they are placed the usual way.

Something clearly has changed but at least I could move forward (as I don't need attachments)

thank you very much. same thing happened to me, and it can be solved by doing this. Thank you very much

This does work, but be mindful that disabling the attachment option will delete any image that was uploaded after the change (because it now sees those as an attachment). I did it on a small list and it is working as described, but I had to re-upload images for each item in the list that had been addded since the change happened. However, I have a much larger list where I do not have the time to do these same steps...

Works only as a workaround as long as you are not using the attachments before… :( I need to have it enabled.

All of my images are in a Thumbnail Photo column and not in the "Attachments" column (your attachments column might be hidden from view). This recent change by Microsoft enabled my "Attachments" column which gave my new incoming photos the "Reserved_ImageAttachment...." name. By disabling the "Attachments" column, I'm back to what it looked like before. All new photos come in like they did a few weeks ago.

To disable the "Attachments" column, go to List Settings > Advanced Settings > select the "Disabled" under Attachments. When you go to Save, a warning will pop up that all your Attachments will be lost. This is only referring to the Attachment column and not your separate photo column. Your photo column will no be affected.

This meant I fixed the problem going forward so to fix the problem for all the images that have the "Reserved_ImageAttachment...." name, I disabled the Attachments column and then renamed the photos by first downloading each one, renaming them, and then re-uploading them back to the individual sharepoint rows. All is back to normal now.