I will close this. It turns out the root cause is related to this other bug I filed:

Found the problem here - I used a different and simpler version of the configuration above and *show openvpn server* returns an output when a client is connected.

Ah! ok, I will close this. Looking at the man pages, seems like open nhrp doesn't have a no-unique registration feature?

@m.korobeinikov - I did not test the backup and fault, but what you said sums it up correctly. Let me know if you need anything on exact re-creation, etc..

Hey - Thanks for the fix works great. One more thing I noticed, I'm not sure if it's an edge case or considered a "bug".

For anyone looking for a work around until it is patched this is my workaround. I am just adding a line to restart the service right after bootup in the “/config/scripts/vyos-postconfig-bootup.script” (more info on this file in the command scripting section - Command Scripting — VyOS 1.4.x (sagitta) documentation)