Previously this did not work correctly - the problem was only visible actually when using Joomla in a subfolder. My guess is you always modified the path to add the slash, even after the image path was inserted by Joomla's media manager. Is that correct?

If a website was in domain.tld/some/folder/ that feature would not create the correct path to the image inserted in that extra field type. This is what was fixed. It's possible your editors manually edited these paths, as when they are added by Joomla, there is no leading slash added (path looks like "images/some/folder/image.jpg").

Thankfully, you can normalize that behaviour with a check in your overrides.

It would greatly help if you provided a URL to your site and at least your item.php override (if there is any) from inside your template's /html/com_k2/default/ folder.

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