Oh, I get it. You're confused by how the delegate voting works.
The article you're citing is from July 30th. Not a single delegate had voted, nor would they until the virtual roll call that started on August 1st.
Democratic delegates are voting virtually to select their new nominee and formally elevate Vice President Kamala Harris to the top of the ticket.
www.cbsnews.com
With 99% of the delegate votes going to Harris when the virtual roll call of voting by the delegates was complete.
Kamala Harris received 99% of the delegate votes in the Democratic National Committee's early virtual roll call vote, which ended Monday evening.
www.cbsnews.com
See, you didn't understand when the delegates actually voted. Not one of them voted for Biden. 99% voted for Harris.
Its okay. I've got you. I'll walk you through the whole process.