This thread has troubleshooting steps you can try.
That said the net is getting absolutely smashed at the moment, all those brand new tech toys simultaneously getting set up and updated really tests the infrastructure. My ISP is giving me speeds about 20% of the usual, across multiple sites and speedtest services. Even the Cloudflare speedtest is giving me a fraction of my usual speed. (Cloudflare has edge servers in most ISPs worldwide, and in theory should be less affected by congestion elsewhere on the net.) Using my VPN was even worse.
If you're having the same issues across multiple sites it would point to the wider net being under stress, hopefully it will subside once all the new PS5/XBox updates are finished and everyone is happily escaping into tech or succumbing to a holiday food coma.
