I was able to fix the issues by adding this code to the additional CSS:
}
.wp-block-navigation-item__label {
display: inline !important;
}
.wp-block-navigation-item__content::before,
.wp-block-navigation-item__content::after {
display: none !important; /* Hide potential icon placeholders */
content: none !important;
}
BUT I still don’t know what is the main reason for this happening to begin with.