Just had this going from beta 5 to beta 6. Reset my router turned on/off Wi-Fi, “forgot” networks and reset them up. It would only assign an up of .2 or .23 when it normally would be in the .170 range. Wouldnt recognize the usb c network adapter either not my phones hotspot. Couldn’t sign in to submit a bug report. rebooted to recovery and it complained about being unable to reach the network when I tried to install, but when I tried again it started to install. With some luck it will be back up and running.