I've gone through multiple people, managers, guides you name it. Might just switch tbh
Have you tried a factory reset of the Smart Hub 2, just in case its downloaded a bad configuration?
It could be that both Smart Hubs 2 work for a while, until a bad configuration file is uploaded to it by the BT management system, and this causes them to fail.
The home hub 4 would not receive or respond to the bad configuration, as has totally different firmware.
You could always try a third party wireless router to see if that works, as it BT would have no control over it.
You would not be able to switch providers if you are still in a contract, without a large cancellation charge.
I have tried multipe factory resets, from the GUI and punhole button on the back, this includes both routers, neither has yet to work. The orgional SH2 I used had a update on the decemember 2nd but it was still working well way after that, this only happened on the 20th, and then its been hell since then
Your money would have been better spent buying a third party router rather than another super hub.