I added income from my 1099-K and when trying to file, I get an error via Form 1099-B, saying the sales proceeds don't match the payment amount on 1099-K. What do I do?

I only have one 1099-K, via Paypal. I only added the Filer's name, TIN and gross amount reported in box 1a (as directed). It's now prompting me to check the 1099-B worksheet entry. Not sure what to change / where the error could be...