Sim update VI Beta installation help

I am on PC. For some reason I cannot use feedback hub with my standard internet connection any more. Standard means I am tethering my phone to get fast LTE internet (unlimited data plan). Now connected via my phone I get the message “You need an internet connection”, which I apparantly have! Switching to the only available public WiFi I can connect to feedback hub, yet the speed is extremely slow. This issue has not been there before and does affect all Microsoft related stuff. Everything else works as usual.