HDHomerun channels not fed through to ChannelsDVR

I am running ChannelsDVR of an QNAP TS-451+. It has been running successfully on this for some time, but had a glitch today, and when restarted said it had no Sources. I scanned the network for the HDHomerun, but Channels did not find it.

I scanned using the HDHomeRun Setup software and it found it immediately, so I manually added it using its IP address.

Now channels is saying

"1 source found

(12524E36)

0 channels on 192.168.1.153

No channels detected on this HDHomeRun. Please scan for channels, then click here to continue."

If I click on the 'scan for channels' link, the HDHomerun web page opens up and is fully populated with all the channels.

I have tried "Reload Lineup" and "Sync Station Mapping" to no avail.

How should I proceed?

Reboot?

Tried rebooting NAS to no avail.
Seen another post talking about port trunking on the NAS causing problems so going to investigate that.

OK seems to be working now.

Investigating trucking didn't solve the problem but the NAS screen I was looking at seemed to imply that the IP addresses for the two ports on the NAS had swapped (I had also rebooted the router while trying to resolve an earlier problem before the HDHomeRun disappeared, so it must have re DHCPed all the addresses).

I swapped over the network cable to the other port and tried a rescan for the HDHomerun and voila it was found with all its channels.

I really should move away from DHCP lol.