From time to time, the delivery of the OTP emails or SMS messages can fail or be delayed. The blockage on any particular day could be anywhere between QR, one of the various service providers en route, and us.

It doesn't help those wanting to make an urgent transaction, but best practice once you can get back into your account is to enable OTP sending to both email and phone, and ensure that your contact details, country code & dialling format etc are up to date.