Sorry if it was already mentioned but Win 11 has a network troubleshooter, so you could try that and also make sure there isn’t any metering enabled. You can do a reset of all wifi settings to see if that clears up the slowness. I got this info from a search and looked at this guide: https://www.guidingtech.com/top-ways-to-fix-wi-fi-not-working-on-windows-11/