I've been having this problem as well. When trying to connect to OCBC Business Velocity, it always asks for OTP after I've authorise the Onetoken through the notification. 

I've found a solution tho! 

At the top right corner of the OCBC Business Velocity App, there is an arrow. 
In there, there is a option named "OneToken". Click that and a "Generate OTP" page will appear. 
Click the "For Account Login" and a 6 digit OTP will appear. Input that 6 digit when QBO prompts you to input your 6 digit OTP. 

All done! Hope it works for yall :)