As part of investigating something else, I clicked on
https://support.broadcom.com/mainframe-software on support.broadcom.com as well.
That hang for me too. A short while later it works.
You might want to start doing some web QA at Broadcom and maybe correlate web requests against support.broadcom.com against the responses from the respective downstream systems, or look at the delivery performance of the downstream systems in general. Not just from the LAN but from sites across the world and with various browsers. I think you should find that to be revealing.
I also found that going to support.broadcom.com with IE11 today results in an endless loading animation as well, which is kind of in a similar avenue.
Kind regards,