I do have ublock origin on everything of mine, so conceivably it's reacting to that somehow. I'm no longer at my computer to be able to look more closely at what it's doing.
Whenever you're running this kind of eyeball test with DevTools, make sure the "Disable Cache" option is _not_ checked. And even then, make sure the requests you're counting were not served from your browser cache. It's possible that only the first page load sends hundreds of requests, and subsequent loads may still initiate those requests, but have their responses served from your browser cache (or your cache is disabled).
I would check myself, but I haven't logged into Facebook in many years. :)