Automatically change daytime and nighttime wallpapers using automations

Hi,

I have two different wallpaper pairs I want to use for when my phone is using light mode during the day and dark mode at night. There is an option in automations to switch to an already configured wallpaper pair, so I thought I could just use this and trigger it at waking up/sunset for the different wallpapers. But the sunset automation does not seem to work and I cannot figure out why. This is how I set them up:

After waking up it automatically switches to my day time wallpaper but the switch at sunset is never triggered. I‘ve also tried creating a shortcut that would change the wallpaper depending on my phone’s appearance (light or dark mode) which works fine when I manually trigger it by tapping it but as soon as I try to run it using an automation it’s not working again. Any ideas on why the wallpaper change is not triggered at sunset?

Thanks in advance!