Dahdi problem after replacing VPM on a Digium TE121

Asterisk version
Dahdi 2.8
FreePBX modules are mostly and .2

I opened a ticket with Digium to troubleshoot a screeching sound on PRI calls.
The problem was traced to the VPM which was RMA’d and replaced yesterday.

The Dell server was powered down normally and unplugged, 121 card removed, module replaced, card reinserted into the same slot, system powered back on.

I had Digium on the phone while logging in through FreePBX.
The support rep didn’t see the PRI channels registered with Asterisk.
I clicked on the “Other” menu in FreePBX and went directly to the hardware page, no Dahdi entry on the menu.
There was a “new hardware detected” message on the screen initially and it faded out.

I had to set the “Signaling” back to pri_cpe for the span to come up and register.
The Digium rep restarted Asterisk and Dahdi - and we started receiving calls.

I wasn’t until an hour later that I started getting reports of outbound call failures and went back in to take another look. On the hardware page now there is a link at the upper left “Install chan_dahdi.conf” I clicked the link and we were able to observer that chan_dahdi.conf was replaced in the file system, with an identical file.

The full log has entries:
app_dial.c: Unable to create channel of type ‘DAHDI’ (cause 0 - Unknown)

The Digium rep said that Asterisk has Dahdi loaded and his thought was that there is a “disconnect” between FreePBX and Asterisk; and recommended I try this avenue.

What additional information should I provide to try to resolve this ?