The plugins seems quite buggy, in sandbox it just not work therefore I straight try it out on LIVE.
1) Chained payment -> When checkout and fill in all details when link to paypal and get message
“We can't process this payment. Try linking your bank account to your PayPal account, then try again.”
2) Parallel payment -> Able to proceed to paypal payment, after buyer pay with credit card and choose “Pay” button then still same get this error message “We can't process this payment. Try linking your bank account to your PayPal account, then try again.”. Although it have this message then I check the paypal account, for seller receive the money however for owner did not receive the money. The commission money just went disappear.
3) For logging your setting there write “Log PayPal events, such as IPN requests, inside woocommerce/logs/paypal-7fbdc18f1a23b25c97d6ff47089c6f98.txt” however I find in my hosting did not have that log file, and did not event have the logs folder.
I been working with paypal staff for few days and yet we found out the problem might come from your plugin