The text color in the WYSIWYG field can be affected by the theme or a plugin style. Please try to deactivate all plugins except Meta Box, MB extension plugin, switch to a WordPress theme (2021) and recheck the issue.
Hi,
there's no conflict with plugins or themes. I've checked and before update It was working properly. It's in visual mode that do not loads the buttons and default styles.
I'm having the same issue. The second clonable WYSIWYG field, doesn't displays properly, after it's added.
If I save the page and refresh it displays normally.