Panel logs out when saving file meta fields


On a live server, whenever I attempt to save an edit to a metafield of an image (file template), I am logged out of the panel. The save is not completed.

I am also logged out when trying to delete an image.

I have tried deleting all sessions, disabling cache of browser, adding the below to .htaccess

<IfModule mod_expires.c>
ExpiresActive off

I am using v 3.5 of Kirby & running php 7.4.

Any help with this would be great.

Have you already check out the troubleshooting guide: Panel issues | Kirby CMS?

You probably mean PHP 7.4…

Thanks @pixelijn, I had only searched the forum and not checked the docs…

In the end the issue was solved by disabling Varnish cache on the server (as was nicely outlined in the docs).