New upgraded calendar view background changed

Hi
After upgrading to the new calendar view, when I use the updated calendar designs, my calendar background color changes to black instead of white. I don’t have any color customization except for the “month view” “Calendar Highlight Colour”.
Can you help figure out why this is happening?

Here’s a link to my staging area where I’ve enabled the new design:
https://silviafindings.staging.wpengine.com/events

Here’s a link to my live website with my original design (old):
https://silviafindings.com/events

Thank you
Lyse

The page I need help with: [log in to see the link]