Eventually figured this out, posting for posterity:
Had already tried booting in safe mode, disabling docker, VM services, no luck.
I randomly visited the unraid ui via my android phone and the pages were snappy, so issue was probably related to the laptop.
I noticed I had an old (~2023) installation of Sophos AV that didn't fully uninstall in the past and parts of its leftovers were related to network services. I attempted removing everything related via regedit, disabling the services, no luck, so I eventually booted through a Windows installation USB and disabled the relevant services via the recovery environment, booted to Windows, ran their official uninstallation tool and after a restart page loading times (Unraid) were fixed.