Invoices are not showing the currency symbol correctly

Dokan Multivendor

@vsplven

Try this code snippet

/**
 * Change "vendor:" to "Sold by" for Dokan invoice
 */
add_filter( 'wpo_wcpdf_shop_name', 'wpo_wcpdf_edit_vendor_name', 10, 2 );
function wpo_wcpdf_edit_vendor_name( $shop_name, $document ) {
	if ( ! empty( $document->order && class_exists( 'Dokan_Invoice' ) ) ) {
		$template_settings = get_option('wpo_wcpdf_settings_general');
		$dokan_invoice = new Dokan_Invoice();
		extract( $dokan_invoice->get_order_id_parent_id( $document ) );
		
        if ( $parent_id == 0 ) {
            if ( function_exists( 'dokan_get_seller_ids_by' ) ) {
                $seller_list = dokan_get_seller_ids_by( $order_id );
            } else {
                $seller_list = array_unique( array_keys( dokan_get_sellers_by( $order_id ) ) );
            }

            if ( count( $seller_list ) > 1 ) {
                return $shop_name;
            } else {
                $vendor_id  = $seller_list[0];
                $vendor     = dokan()->vendor->get( $vendor_id );
                $store_name = $vendor->get_shop_name();
                $store_name = ! empty( $store_name ) ? $store_name : __( 'store_info', 'dokan-invoice' );
				$shop_name = $template_settings['shop_name']['default'];
                return $shop_name . "<br /><br />" . __( 'Sold by: ', 'dokan-invoice' ) . $store_name;
            }
			
        } else {
            $vendor_id  = dokan_get_seller_id_by_order( $order_id );
            $vendor     = dokan()->vendor->get( $vendor_id );
            $store_name = $vendor->get_shop_name();
            $store_name = ! empty( $store_name ) ? $store_name : __( 'store_info', 'dokan-invoice' );

            return $shop_name . "<br /><br />" . __( 'Sold by: ', 'dokan-invoice' ) . $store_name;
        }
	}
}

Use this guide to see how to apply this snippet to your website.