BT Smart Hub 2 and firmware updates

[#1]

Just bought a BT Smart Hub 2 off eBay as I got fed up with the Wifi disconnections with my Plusnet router, only had it a month.

Read some of the posts on here , BT can force a firmware update and you lost your login and password settings.

How often does this normally happen and can you disable it from automatically doing this?
I'd prefer to do manual updates. Would be a major PITA if I was away and it automatically happened

[#2]

With my smarthub 1 the firmware updated ok and never reset the username.
I don't believe it's a common event, nor do you have any control over it.

[#3]

I strongly suspect the resetting of the username is more to do with the diagnostic interception capability of the hub, rather than any firmware update activity. The BT Smarthubs can force connected devices through a troubleshooting flow in the event of service interruptions (e.g. brief loss of broadband signal) and one of the resolution outcomes is for the hub to try resetting the PPP username to the BT default. When used on a Plusnet line, this obviously causes problems.

Not much you can do about it.