Also some talk of Voxi fixing their lack of data capping. Some subscribers have received messages from support about this.
They did message me back after a week saying it was fixed but I just decided to leave them. Interestingly I went to Three and no issues, better speed (albeit different router).I don't know if this is sheer coincidence (have three actually fixed the issue?) but yesterday I installed a HuaCtrl app on my phone (android) and started playing with the manual band settings. Am now set to Band 3 (1800 Mhz) and all good again on 4G - sites which refused to load are now loading quickly again.