Essentially, I have two PayPal transactions for the same day (31/3/21) and the amount. I can tell from my PayPal account which one is genuine. So my question is, should I just delete the bad transaction, and its payment of course? And I wonder where it came from - did I create it manually, before I had automatic feeds?
I can see that you are in the invoice view at the moment, if you go into the one which was created in error, you will be able to see the invoice history which will tell you how it was created.
If you are 100% sure that one of them was created in error, you can just delete it as your normally would, you will also have to delete everything that is linked to it, for example, the invoice has a transaction linked to it, so if you believe that the transaction and the invoice are in error, you would need to delete both of these.
I hope this makes sense, but if you have any further questions, please don’t hesitate to ask.