I have had this issue on other sites before. Usually it is solved by going to Paypal settings and set “Paypal Balance” as default online payment option.
But I have this option set and Pling would not accept this option for the supporter donation. I do not want to have my card charged, I pay fees when I receive money, I pay fees when I transfer that money to my card, I would then again pay fees when making the donation (apart from the fees on top of the donation). If you search the last sentence for the word “fee” you get the idea…
Please double check that Paypal Balance can be accepted for the donation payment checkout!