I suspect that it might have lost its Z-Wave network address. As far as I know, it is not possible to give it back the same address. It will need to be re-joined and will get a new address.
Is the issue is that you have several automations linked to it and you don’t want to have to modify them?
If so, you could always try this procedure which will allow you to update the Hubitat device with the new address:
