That's interesting, but I wonder....
Yes I must admit I hadn't tested them all myself but my Firefox browser, (Mozilla), also failed tests 2 and 4. I believe there is little we can do about that because it depends how the web site is coded.
But I wonder. When I loaded that web site in FF my Zonealarm firewall popped up a message warning me that Firefox was trying to act as a server. Whilst FF has automatic access to the internet it does not, on my system, have authority to act as a server itself and so ZoneAlarm asks me for permission.
Whilst you do not seem to have a problem with FF acting as a server, (you may not have seen any videos if you had), I wonder if this problem is a firewall issue on your computer.
Do you have a firewall installed on your computer? If so, which one? it may be that either of the browser types have different permissions in the firewall settings.