Okay, this time I am giving you an ultimate tip to solve your problem. This simple hack will never show that endless spinner on your woocommerce checkout page again. Follow the below steps.
1) Go to the control panel (Cpanel or any alternative) and then click on the file manager tab
2) Browse to the folder publichtml/ or wordpress installation folder
3) Then go to the folder wp-plugin/woocommerce/templates/checkout/
4) Find the file named review-order.php
5) Delete it!
This review order file is for reviewing the shipping address input fields on your checkout page. Even if you delete it there won't be any issue to your cart or checkout page. So it is safe to delete it.
After deleting this file you will never get that problem of endless rotating spinner anymore on your woocommerce checkout page.