M6 continually shutting down

At one week old this router has been continually shutting down, doesn't matter if the battery is in or ac power. Was doing it several times a day, now every few minutes.
Partner has the same unit on the other side of the country and has the same problem. No help from telstra.
Internet search shows this is a common problem, is there any fix in the way?
Ran the m5 for over a year with almost no problem. Very disappointing.