It's likely being retried on a lower level, similar to the sibling comment about CORS.
Dev tools are not intentionally hiding the retry from you; from its perspective it's asking the networking layer to fetch a page, and the fact that that layer retries beneath the scenes is invisible to it.
Yeah, that was my thought as well. It threw me for a loop because I never would have expected that my browser dev tools would hide something like that. It was a core tenant of my debugging that was broken.
Dev tools are not intentionally hiding the retry from you; from its perspective it's asking the networking layer to fetch a page, and the fact that that layer retries beneath the scenes is invisible to it.