So I just authenticated and then tried again and was receiving a 401 from my server so I decided to see what was going on. What I found was that the expiry time saved after I authenticated was different to the time on the token. The expiry time saved was:
1521192854
Date in your timezone*: 3/16/2018, 11:34:14 AM Standard Time)
And The expiry time on the token:
1521188858
Date in your timezone*: 3/16/2018, 10:27:38 AM Standard Time)
This is really frustrating.
First time this has happend