I have the same problem and I'm not able to set up the UOB App. I neither know the amount I owe, nor how to pay. Didn't get any proper info, tried the call center multiple times for looong but no avail.
Now I have to go to a UOB branch and get help for set up the App.
This immigration from Citi to UPB is pain in the A$$ and customer service from UOB is non existing.
This situation sucks and I am close to ditch this card and get me something else.
I hate that I now have to run after these idiots to make sure I pay my due.