Add me to your list. I've two HH6 sitting in their boxes and have gone to a third party router with Huawei HG612 modem. I use the two HH5 I have as my WiFi.
The latest hh6 firmware is ..................last three numbers are 244, this was updated on my hub on 26/01/2017.
last time I had this issue with line drop out ( yes, cabled connection to router) I was sent a new Hub 6 - this now has firmware SG4B10002244....its better, and been stable for a while, but, since a MCB trip on my soickets, the line has gone several times...if I put my old router back on, it connects, then put the 6 back on, and it then connects again... they have a serious issue somewhere with the way the bu connects to the exchange...