Had this problem now for a very long time, and recently came back in touch with it after I was forced to use my HH5 as my TPLINK ADSL router got bricked.
The problem only persists when using any BT issues router whether it be a HH3-5.
The event log is filled with firewall packet loss and blocked entries which I understand that is the firewall doing it's job which is fine. The line that keeps popping up is the one in the title of this thread (PPP LCP Send Termination Request [User request]) this pops up every time the connection drops.
that was a Mod saying that is does not cause a drop in connection - I can't see why that still does not apply to a HH
To reproduce this fault all you need to do is to go to
enter your phone number and press the continue button.
This results in the hub light going red and the following initial error log
18:09:29, 06 Sep. (32098.880000) PPP LCP Send Termination Request [User request]
Your local end does not reboot as nothing is in the boot log.