My chumby/dash also has this problem -- 'internet is unreachable'. (Got power cycled...)
When I do a packet trace I see it successfully gets it's ip address via dhcp, resolves names via DNS, send/receives packets to/from the internet, and finally gets a 403 forbidden from the sony servers.
Here is the DNS response:
q: A? ssm.internet.sony.tv. 3/0/0 ssm.internet.sony.tv. A 188.8.131.52, ssm.internet.sony.tv. A 184.108.40.206, ssm.internet.sony.tv. A 220.127.116.11 (86)
Here is a get to 18.104.22.168:
GET /DASH/index.html HTTP/1.1
User-Agent: curl/7.16.2 (mipsel-unknown-linux-gnu) libcurl/7.16.2 OpenSSL/0.9.7l zlib/1.2.3 c-ares/1.3.2
and here is the response:
HTTP/1.1 403 Forbidden
Date: Fri, 18 May 2018 02:11:30 GMT
It then tries the other addresses, which fail, and then gives up...
So, more than one dash has the problem.