PayPal Advanced charges $0.00

-- HikaShop version -- : 3.0.1
-- Joomla version -- : 3.6.5

Hi,
I am setting up Hikashop based online store and have strange problem with PayPal Advanced plugin. It transfers customer name and address to the payment gateway, but the amount is always $0.00 (see attached image). I tried to activate debug, but the report file is not created. Payment log file location is set to media/com_hikashop/upload/safe/logs/report_526840422.log Both safe and logs folders are writable (777).
I am also using regular PayPal plugin for PayPal Express method and it works correctly.

Has anyone experienced this behavior ? What could be the problem ?

Thanks.
Best regards,
B.G.

Since debugger does not work, I temporarily added file_put_contents command to paypaladvanced.php file and saved the value of $postdata into a log file. I found that AMT in POST message is 0, that's why PayPal shows order amount 0.
Further debugging revealed that the value of $order->cart->order_full_price is empty string, which is the reason the following line returns 0
'AMT' => @ round($order->cart->order_full_price, (int)$this->currency->currency_locale),
The value of (int)$this->currency->currency_locale) in my case is 2.

Now the question is why $order->cart->order_full_price is empty?

Thanks.

Found and fixed the bug. Instead of
'AMT' => @ round($order->cart->order_full_price, (int)$this->currency->currency_locale)
it should be
'AMT' => @ round($order->order_full_price, (int)$this->currency->currency_locale)

It is working correctly now