Sounds more likely that your OS just had less things going on and your browser not as many extensions running as your daily driver browser.
Why not the TLS implementation? The video drivers and their kernel interfaces? The OS' process scheduling? A dozen other things that might be responsible for the perceived performance difference to one degree or another?
It feels like gamers who blame 90% of multiplayer issues on "the netcode".
It'd be different with data looking specifically at TCP connection establishment timing without a bunch of other stuff involved.