Advertisements When I try to activate the service on my Roamio Plus, the HBO GO site says Time Warner is not one of the available HBO suppliers once I select the TiVo as my device. I'm in Los Angeles. There are a hundred minor, tiny cablecos, including a bunch of local University outlets available, but Time Warner is not one of them. I had no problem activating HBO GO on my three Rokus, so this is not a Time Warner problem. Why roll out a feature that doesn't work on one of largest cable suppliers in the country?