I had that until I bought the levelling bar then when in inn 20 mins, another tip I seen is to extend some 10mm studding on two holes in the bellhousing to locate engine
Are you sure the clutch is *really* centred? How did you do it?
When I was doing mine, I used a clutch centering tool and thought it was OK, but couldn't get it together. I ended up taking it apart, slackening off the clutch housing bolts until the clutch plate was just about held in place but could be moved, and then mated the engine and gearbox. It all went together OK that time, so I carefully separated them again, and tightened the clutch housing bolts to torque. Repeated the mating, and all went together pretty easily next time around. A faff, but ultimately probably quicker than trying to continue with the clutch plate slightly out of position.
Unless you have a really good, tight clutch tool, I think there is too much slop in them to be 100% reliable (or someone who is careful enough to use them properly). In retrospect, I should have realised mine was too cheap to be really good, and I'm definitely not skilled enough to compensate for its sloppiness.