Free Shipping not being selected

Under freeoptions I give free shipping for orders over $100 coming from shipping zone Lower 48. Otherwise that zone' shipping is flat rate $4.99

The problem is when a buyer starts the checkout with less than $100, $4.99 shipping is automatically selected, and then the buyer continues shopping and adds to the cart pushing the total past $100. When checking out after that, although free shipping is now available, the flat rate shipping remains selected and the buyer must manually select the free shipping option.

How can I get the checkout to recognize that the new cart total should now trigger free shipping?

Still need help. Anyone? Anyone? Bueller?

I am the customer and I picked Next Day ...

Then I went and added more to the cart, which took the price to over $100 so you will give me Free Shipping Option on that slow boat when the mule gets around to getting there ... and I don't see that you did this ... :flex:

Instead, perhaps make the Free Shipping Option read in bold or red or something so that it stands out and put it first in line for when it displays ...