Hello @typk ,
Welcome to the Community.
Interesting case. For one solution, did you delete any previous time delays from the Flow? Could you please confirm if there was a time delay placed previously before this email previously, which was deleted recently? If this is correct, you could use backpopulate to send this out. Did you update the time delay after profiles were already queued up for the email? If that is the case, profiles will always queue for the time delay based on what it was when they first triggered the flow, and not reflect any updates you made to the timing of the flow.
Thanks,
Alex