yes.
it's a bug of COD extension.
To fix it needs to replace
$this->view->assign('back', $this->html->getSecureURL('checkout/payment'));
by
$this->view->assign('back', $this->html->getSecureURL('checkout/payment','&mode=edit',true));
inside file public_html/extensions/default_cod/storefront/controller/responses/extension/default_cod.php line 39
thank you.