I receiving a 504 Gateway Timeout error when I try to pay via PayPal or Stripe in Woocommerce. PayPal in Sandbox mode also causes an error with ajax request, although in the PayPal logs it is written that the payment was successful and in the WP admin panel it is clear that the subscription has been extended. Tried to disconnect plugins, it did not help. max_execution_time set to 500, also did not help. I did not try to change the theme yet, the Apache server is work on it. What else can I do?