It happened sometimes due to system failure. Sometimes OTP delay until timeout. Then you request another one than another one. Suddenly you get OTP but when you keyed in, it is wrong because it was for the previous request. Happened 3 times before last time. Once I get the OTP code the next morning

That is the bank problem and will piss off its customer thus probably migrate to other bank. I'd say this is not security issue that will compromise customer.

One bank need OTP:
1) To login.
2) To create favorite account but still need another OTP to transfer money
3) To transfer money to 3rd party account.
4) To make payment
5) Reset password

Another bank need OTP:
1) To create favorite account and subsequently need no more OTP to transfer money to favorite account
2) To transfer money to 3rd party account
3) Reset password

Although looks like less security, I still prefer the 2nd bank

It is not as easy as you think. Different channel different server. You send SMS probably just loop local network. The TAC request goes through several networks. So still depends on how telco network and bank on how they structure the network.

Bank 1 is AmBank, and I think CIMB and probably others too.

Bank 2 is Maybank

Luckily it is very rare case for me.

I forget about the CIMB login, but I remember that transfer money to favorite list still need TAC. I'm no more using CIMB since the company is now using AmBank ( even more rare location )

I transfer monthly salary to my Maybank . More accessible