My daughter just went into Vodafone to enquire about the $20/365 SIM and was told that to use it overseas even to receive SMS would cost around $5 per day Global roaming.
Have you received SMS OTPs on yours lately? Maybe it's a new policy same as Telstra now.
I also cannot receive OTP on my DTAC number from the Commonwealth bank of Australia but OTP from Westpac bank comes through instantly.
Awaiting Commonwealth to tell me what the problem is, so frustrating.