I've been having problems since December 2019 as well.

Nothing works at all. I tried using the app to manually generate a code and was able to enter it into the QBO prompt, but after proceeding I received an error message. 

It's been many many weeks and the problem still exists.

I think the only way would be to contact OCBC to revert back from OneToken to physical token device (which is rather inconvenient to carry around) , or move over to another service like Xefo.