Files does not generate thumbnails for mp4 files on Ubuntu

[poldi171254 (Poldi)]

Sorry, but I posted the issue again and have progressed

Nautilus does not generate thumbnails for mp4 files in Ubuntu 24.04

I deleted .cache/gnome-desktop-thumbnailer .cache/gstreamer-1.0 and rebooted. After logging in .cache/gstreamer-1.0/registry.x86_64.bin is created. After starting nautilus and going to a folder contaning media .cache/gnome-desktop-thumbnailer/gstreamer-1.0/gstreamer-1.0.registry is created. Is there anything spcific I can check for in the registry?