TurboTax added $460 due to the extension I just filed after TaxCaster confirmed I am due a $762 refund and Line 4 shows 0 tax liability? Line 6 shows $460 due?

I am surprised their algorithm did not pick up such an obvious contradiction, unless Line 6 in Part II on Form 4868 is showing the Balance Due to me, rather than from me? Thanks ahead of time for any explanations that the community can provide.