Did I set up configurable products wrong? Or is this intended functionality?

Magento has the ability to link to a configurable product with options already specified by adding the attribute id and option to the query string, like this:

www.example.com/product-link.html?size=large

If we have 3 sizes, small = $5, medium = $10, and large = $20, the “base” price is visible when the user lands on the page, for about 3 seconds, and then the price updates to the large variant price ($20)

The problem is, although we have appropriately implemented structured data, during the time that the incorrect price is shown on the page, Google’s crawler detects the price for the large variant as being $5 instead of $20.

This is what the configurable product looks like in Magento:

And here is the simple product referenced by SKU in the mapping URL for the configurable product:

This is set up correctly, isn’t it?

If so, why does the incorrect price display on the page for a second or two before the price and size dropdowns update to the correct one?