As I recall, a DND will persist through a system reset. If the RAD port is within the embedded voice mail on the MX controller, you have to clear the DND from the Maintenance Terminal. If the RAD port were on a per node port, you could do it with the 'Clear Features' command from the console.
To do it from the Maintenance Terminal,
Login and enter the Maintenance Function
Select F3 DIAGNOSTICS,
Select F2 CL_R FEATURE
Select F2 DO_N_DISTURB
Select F1 BAY/SLOT/CCT, input the location of the RAD port that's in DND, and ENTER to clear the DND.
To avoid future problems, extend COS Option 404 in the RAD COS to be longer than the total time of the recording(s) in the set.
If you add RAD ports, check that your system is equipped with enough DSPs for the total of VM & RAD ports.
Harry