G'day Geo, and welcome.
Yet another point to be aware of is backlash. When centering on your alignment stars the final movement should be with the right arrow and up arrow buttons. This removes backlash error.
So when centering, overshoot the mark with the left and down arrows then centre using the right and up.
Also, setting to 27deg using the dial may not be accurate enough. Get yourself a
digital inclinometer.
There are cheaper ones around. This will be a much more accurate way of adjusting latitude.
Cheers, Kev