I only tried IBFT from other banks to AmBank savings account and loan payment, no issue.

Forgot to mention just now. They were Maybank and CIMB.
I used it when BNM requested banks to give free IBFT for 3 months.

if not mistaken, certain bank does not allow IBFT to pay ambank cc..
try to check the list

No problem. Transfer from HLB and CIMB. Check your Online Transfer limit.

Yes, for PPL, it is the best for now. Plus it has some overseas PPL too.
Err?
1) CS - Dependant. I have no issue with AmBank CS. In fact they are very helpful for my case.
2) No AF for AmBank cards that I have. In fact, I think none of their cards has AF. I could be wrong though.

Yes, my problem isn't caused by the CS. You can tell that they're trying - some even called me with a follow up (and I could sense some frustration with the situation in their voice too).