Ding doorbell shows in app, but "offline" on NVR

Lost the password on my ZP-NM28 NVR and had to reset the whole unit. The wired cameras returned fine and a pair of wireless cameras are back up, but my Ding doorbell won’t go online on the NVR. I can see and use the Ding in the Zmodo app, and it was found and added to the NVR, but shows as “offline” on the NVR. Even tried deleting the Ding in the Device Management and letting it be found again, but still shows up as “offline”. Worked fine before the reset. Any ideas on getting it to show up as online again?