Stuck MWI on 7960

I have phone that is stuck with the MWI on.

It’s a Cisco 7960
I removed the voicemail directory. I recreated it with addmailbox. I can leave a voice message, login, delete it. The MWI is still present.

What can I do to investigate this further? Hard reset the phone? “restart when convenient” hasn’t helped.

Thanks.

Jon