You can go into Debug mode >> Home Screen >> Payment Transactions to see all the payment transaction records.

If the payment transaction went through, the payment, acquirer reference, transaction type, and validation date fields would be filled by the system:

Also on the system would log a note on the Sales Order indicating that the payment was pending / completing.

The problem is coming from PayPal side. 

Things to check for: 

• Is 2-factor authentication turned on?
• Does Paypal have a minimum transaction amount?
  
  

At this point, I suggest to contact PayPal.