Hy guys, I've forwarded the details across to the app team.
I've tested a colleagues S8 with Android 8.0 & the latest version of the MOA - 4.21.1
The widget seems to be working fine.
Hmm, the OP confirmed he was using an S7 Edge.
The app team haven't recevied any further reports (other than what I've sent them).
They'll keep an eye out.
Thanks @Person, I'll pass this on.
For me the issue was fixed by deleting the My Optus app completely, re downloading it and signing again. I then just had to pick the right number (I have two numbers on my account) and then re adding the widget. Hope this helps.