I have a front-end plugin which allows users to modify the fields (user_meta) of their profile, and everything works except the wp_editor.
<div class="">
<label class="" for="dokan-store-about"><?php _e( 'About Us', 'dokan' ); ?></label>
<div class="dokan-text-left">
<?php
$content = get_user_meta($current_user->ID, 'wpcf-store-about', true);
$editor_id = 'dokan-store-about';
wp_editor( $content, $editor_id, array('textarea_name' => 'dokan-store-about') );
?>
<textarea name="hey"><?php echo $content?></textarea>
</div>
</div>
and the saving part (which works for the image field, not for the wysiwyg)
$store_image = $_POST['dokan_store_image'];
$store_about = $_POST['dokan-store-about'];
$store_id = get_current_user_id();
update_user_meta( $store_id, 'wpcf-store-image', $store_image );
update_user_meta( $store_id, 'wpcf-store-about', $store_about );
As you can see i hardcoded a textarea with the same content, and if i save it like
update_user_meta( $store_id, 'wpcf-store-about', $_POST['hey'] );
it works fine. So i don't see what is going wrong.