I'm having trouble watching the EPL on my new phone. I had it on my olds phone & my tablet and when I go to watch on my new phone it says I'm logged into too many devices. I've logged off my account on my old phone, so I would think I could log in on my new phone.
You're only allowed to have 4 "registered" devices per account. Logging out of the app on your old phone doesn't deregister it though.
On a PC, go to sport.optus.com.au and log in. Then click on your username in the top right hand corner and select settings. Follow the prompts from their to deregister your device(s) and you should be fine to then register your new phone.