Anyone had OTP issues after porting over to VIVIFI?

Thinking to port over from M1 to something else after getting a slowed down experience (I felt that) for the past few weeks, VIVIFI being affordable and is using Singtel line, it seems like a better choice for trial.

However, I came across some users' review on Google, alleged they are having OTP issues right now which is yet to be resolved. This issue messed up their access to banking apps and some other websites using OTP.

Any experience to share will be greatly appreciated.