This snippet is used in the following knowledge base article – https://kb.wpbeaverbuilder.com/article/255-add-underlines-to-link-text-beaver-builder-theme
/* Remove underlines from nav menu links */
nav li a {
text-decoration: none !important;
}
/* Remove underlines from header logo area text */
.fl-page-header-logo a {
text-decoration: none;
}
/* Add default underlines to Page Builder and BB theme link text */
.fl-builder a {
text-decoration: underline;
}
a {
text-decoration: underline;
}