my_remove_buddyboss_pmpro_styles.php

<?php // copy from below
/**
 * Remove BuddyBoss theme's PMPro stylesheet.
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */
function my_remove_buddyboss_pmpro_styles() {
	if ( defined( 'PMPRO_VERSION' ) && function_exists( 'buddyboss_theme' ) ) {
		wp_dequeue_style( 'buddyboss-theme-pmpro' );
		wp_deregister_style( 'buddyboss-theme-pmpro' );
	}
}
add_action( 'wp_enqueue_scripts', 'my_remove_buddyboss_pmpro_styles', 30 );