Is there an item limit for ItsDeductible? When I import into TurboTax, after several items, it lumps the remainder as "custom items" which exceeds $500.

Below is the last line in the details for what is a long list of donated items. 

CUSTOM ITEMS OVER $500
04/21/22 28 Book: Hardcover @ 7.46 $1,184.27

I did donate 28 hardcover books, but used the guided valuation ($7.46 per book)