wp core update not working anymore

What is inside your version.php file?

File: /wp-includes/version.php
1: <?php
2: /**
3:  * The WordPress version string
4:  *
5:  * @global string $wp_version
6:  */
7: $wp_version = '4.7.1';

You can play with that number and test.

You can try to install the latest version of WP Cli and test.
You may update to WP-CLI version: 1.1.0 if the older version had problems. (I found out you used the 1.0 version of WP-CLI before).