How did you know you the credit card payments did not qualify for the bonus interest? Did you confirm with customer service or did you assume that is the case?
Did you managed to get the full 4.1% after trying with IBG then to other banks?

I also experienced not getting the correct bonus interest recently for OCBC 360 Account-i. I fulfilled all the conditions but did not get the full bonus interest. I checked with customer service and was told I did not spend RM500 on my debit card. I checked my transactions online and the total spending was indeed RM500 or more. Some were posted as MyDebit while others were posted as Mastercard transactions. Maybe that was the problem. I forwarded the records to the bank and still waiting for their response.

Anyone else having this problem?

If you open account with ocbc al amin branch (islamic banking) then must use debit card to fulfill rm500 spending. Islamic branch do not have credit card.
If you open account with ocbc conventional branch, then must use their credit card instead.