I have no idea why (TN2 has so many settings I could have changed anything and never find the right combo again) but now when I go to change from my 6 max hud, to my HU hud when we are HU in a sng TN2 will just never let me select a hud, as soon as the list of huds pops up, they vanish again as though focus is being stolen from the tables stacked behind (even though they don't actually pop through).
This is PRETTY annoying as HM2 can't even recognise I'm HU so I'm left trying to do it manually, now, even that doesn't work :-(