to complete the checkout, it takes more than 30 seconds after update joomla

[mosdata]

hello,

My web had joomla 3.6.2 and upgrade to 3.6.4
VM 3.0.16
PHP 5.6.27

The website works well. But when I click the button to complete my order, it takes more than 30 seconds to display the message Your request has been submitted.

It takes so that users think that does not work anywhere.

Could you help me?
regards
Hernan

[mosdata]

Any idea?