Same issue here. I'm being told by chat I'm the only one reporting this.  BS. 

I've tried a chromebook and a PC. I've updated chrome on each. I've tried incognito.  I've tried the same chromebook and PC on 3 different internet service providers. Internet speed tests show 75+ mbs.  I bought a NEW Chromebook today and still have the same issue.  I cannot run my business this way and am getting nowhere with support.  And this is what the browser compatibility tool gives me: 

403 ERROR
The request could not be satisfied.
Request blocked. We can't connect to the server for this app or website at this time. There might be too much traffic or a configuration error. Try again later, or contact the app or website owner.
If you provide content to customers through CloudFront, you can find steps to troubleshoot and help prevent this error by reviewing the CloudFront documentation.