Teamviewer 11 Authentication Rejected

I'm able to remote connect to my pc from my phone while I'm in the same room but as soon as I leave my house and try to connect it says Authentication Rejected. I definitely have 4G or wifi access on my phone so I don't understand why I can't connect.

I've tried restarting my laptop and even though it works on first connection (remotely in another location), the problem occurs again when I try to reconnect for the second time.

Any ideas?