Flip boxes live different from wordpress editor

This worked originally, however now I see that when you hover over a flip box, instead of flipping to the color I have chosen it is just white. Which in turn makes the white text invisible. Any idea how to remedy this?

I am using WP 6.02 / php 8.?? / Everything works but the flip colors.

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