I have had problems with the web-based app not being able to connect remotely on my iPhone. I tried Safari and Chrome. The iPad app always seems to connect remotely.
Today I saw in the forums that the Plex channel was available (though still Beta) so I logged in remotely to my home PC and added the Tablo channel to my Plex server.
I brought up Plex on my iPhone and it found my Tablo and seemed to work fine but one channel wouldn’t stream live TV. It kept giving me some unknown error. So I opened the web-app in Safari and I just keep getting connecting/disconnecting/reconnecting over and over. I tried it in Chrome and the same thing. The iPad app connects fine.
I have had this happen before and if I go home and re-connect the web-app locally it will work fine again.