When it wasn't redeemed.
I checked the status of my 2018 Hawaii state income tax refund last week and the Hawaii Department of Taxation (Hawaii DOT) stated that it was already redeemed with the following message:
Our records indicate that your refund check was redeemed on Feb-06-2019.
If you did not receive and cash or deposit your refund check, please call the Interactive Voice Response System at the toll-free number provided in the Support section.
The bank that I sent my refund to didn't receive any money from the state. I called that "Interactive Voice Response System" and I received the same status.
I'm assuming the Hawaii DOT marked my refund as "redeemed" despite not actually sending my refund.