Hi Omar,
I double checked, and the render option is on for all elements.
Martin,
I’ve uploaded the blend file to Google Drive
https://drive.google.com/file/d/1PLnT5R63ENosyjqtXaJ4aoXMZ2iIiwyG/view?usp=sharing
One weird thing I’ve noticed today, when I reopened the file, is that the ring was also not rendered in the viewport.

I fixed that by going to the data section of the ring, and re-selecting the curve (even though it IS selected, just like in the picture). I’ve just clicked on it, and selected again, and the ring appeared.
I’m on 4.1.1 version BTW