Having spent nearly 1hr on the phone, being transferred 4 times, cut off twice, I am taking a break from Customer Services and trying on here...
Setup: V6 Box downstairs, direct Ethernet to 2AC Superhub TiVo Box upstairs, Ethernet link via Powerline NOTE: Ethernet/Powerline all working as expected and multiple configurations tested without success.
Up until yesterday evening (and for last few months), could view/watch programs recorded on either box from either box. Worked as expected, no problems.
Last night, suddenly the TiVo box stared throwing up Error V106 "You cannot play shows from The Living Room TiVo Box as it is not in the same account" The V6 box also now states "The bedroom TiVo box could not be found" Error C423.
Rebooted both boxes and Powerline (several times) Changed setting (from another thread) for Remote Control to "Allow"