Zend certified PHP/Magento developer

We are getting a lot of PayPal declines. How to find out what is causing that and how to fix?

Magento 2.4.2-p1
Smartwave Porto theme
Amasty One Step Checkout and other Amasty extensions
PayPal Payments Pro set up in the Admin panel

We use PayPal to process payments on our website (via the PayPal Payments Pro option in the Magento Admin panel). We have been getting a lot of declines. We are unable to find out the reason for this (PayPal has not been helpful at all).

Is there a way for us to get down to the bottom of this – find the reason for each of the Declines? What are some good steps in order to try to fix this? We used to process payments manually via PayPal on Magento 1 and never had this problem before.