I live in Carterton and about a month or two ago I also noticed that I no longer get Maori TV and The Te Reo channels.
Every other channel has a perfect signal.
An Auto re-tune, then a factory reset and another re-tune still won't bring them back.
Try a manual tune on Channel 39 and/or 38 depending on your location.
You may also find your auto-tune has found them but allocated them a LCN of 800 or higher instead of their normal LCN numbers. I seem to remember that with my Panasonic I had to do a manual tune and rearrange the logical channel numbers. The FW doesn't allow for correct tuning of the new MUX.
I also can't get Maori TV & Te Reo channels, after a full re-tune.
I have emailed a contact at jda, who are responsible for the Wairarapa transmission, pointing them to this thread.
I will report back if there is anything to report.
We are looking into this.