Is "System Default Theme" supposed to switch between bright and dark?

Nextcloud version (eg, 20.0.5): 27.0.0
Operating system and version (eg, Ubuntu 20.04): Mint 21.1
Apache or nginx version (eg, Apache 2.4.25): 2.4.52
PHP version (eg, 7.4): 8.1.2

The issue you are facing:

Regarding the system default theme: The image shows a slash, with half the display as light and half the display as dark. Does that mean it should be dark at night and light during the day?

It doesn’t seem to work that way. It’s not light during the day. I’m not sure I ever see it light.

Is that because I have dark mode also selected in my browser or in Windows? Or maybe is it because I’m in a specific time zone?

Thanks.

Bingo!

Go to yourDesign settings from your Windows and choose for a light design and you will see, that the design of the nextcloud website will change to light as well.

Thanks! I guess that makes sense.