Bundled product error on square app transactions

I created several bundles of books sold at events via square. For example, selling books 1-4 in a series, together for a single discounted price and transaction.  When receiving the app transactions, I get the following error: "We couldn't Add the transaction(s) due to "Enter an amount of zero for bundled line items.". Check account mapping in advanced settings and try again."

Each of the individual books/items has a sales price (that isn't zero). 

All the videos I've looked up about bundles talks about it in the context of creating invoices, rather than receiving app transactions.

I'm lost on this. Please help!