I have tried about 10 different devices on three different WIFI and I only get up to 20 percent. Once it makes it to 20 percent it says my device has been disconnected. I also tried to connect it by QR code, enter the code, and USB... all nothing. I am using a Samsung Android and a laptop. I have updated everything
Then try using a different web browser. E.g. Chrome or Firefox.
Try a community search for similar:
https://community.appinventor.mit.edu/search?q=companion%2020%25
is your phone /android emulator 's ip is same in the first 3 section?