The answer was not exactly obvious. After reading everywhere about intel trust execution needing to be disabled, I decided to attempt to disable anything to do wit bitlocer. On my specific hybrid, there was a setting labelled "secure boot mode", there were a few options here but I tried to just disable it. Hey presto that was the sucker. I hope this helps someone else.
Edit::
Above answer was actually incorrect. If you change the bios setting on my laptop, then shutdown and start up. nothing happens. if you then restart the computer a whole load of hardware fails, butttt intel VT works finally lol. It must have been dumb luck it worked before. But the shutdown/restart combo works predictably. Unfortunately it totally knocks out some of my other hardware (touchscreen, key lights) rendering this entirely freaking useless :(