If BT sent you a replacement hub it is unlikely to be anything to do with the firmware update on previous hub. I like many others have had the new update without any problems and can be seen by number of posts about the firmware
Check your system to see when the firmware update was applied ( and if you re on the same version I am on) and when the drop outs started being more frequent.
My phone socket is number 7 . Its the only one , there are no extensions
That one is prone to connection problems.
You need to connect things up as shown below, and see if you still get disconnections. Leave it like that for a few days.
That's odd though, I've not moved or disturbed any equipment or cabling.
I did move the hub about 6 months ago however the logs show repeated disconnections beginning shortly after this update.
I still need to perform the factory reset on the device, trying to find a time when I am available for the necessary in-house it work that will require.
I don't have any microfilters. My Hub connects directly into the faceplate pictured in number 7 above. Its a FTTC connection if that makes any difference. There are no extensions off this master socket. The socket itself was installed roughly 6 years ago by a BT/Openreach engineer, and the only phone in the house plugs directly into it, the Hub into the other socket.
In this case, will using the Test Socket do anything, as there is no in-house wiring to eliminate.
Its the connection between the Mk4 faceplate and the test socket that is the issue. The only way to prove it is by using a microfilter, they are not expensive.
You may like to read all of that thread, as the PCB was faulty.
PS. BT Openreach do not exist.
I'll also add qualifying by using BT/Openreach means nothing as BT also use Qube engineers (so called engineers) as "in house" techs.
@Keith_Beddoeis right, the MK4 faceplate causes more problems that any other and was only introduced because the majority of users didn't know how to use a screwdriver.
So, quick update on this. I haven't made any config changes, haven't even found the time to reset the router to defaults. ~My connection has been stable for the past 15 days and counting....