oysterquartz,
Have you submitted a support ticket about this? If you have only mentioned it here then you should be aware this is not an official Runbox support forum and our support activities are focused at
https://support.runbox.com
Setting the time is crucial as beeboy has said. There is no tolerance outside of the correct 30s period for entering incorrect codes. We may look at this if it affects too many people, but so far only a handful have got in touch with us and in most cases it was a time sychronisation problem.