hard to pinpoint the exact reason, could be a number of things @davidjames
How were things over the long weekend, did you run into any issues?
When it comes to these sorts of enquiries, the more information we have the better @Madmick76
Are we not recognising your Optus Sport login credentials as valid, or is there some sort of authentication error that's not allowing you access to the app?
Let us know, we're happy to try and help out.