The problem is always there. Once the bridge has turned from two aligned tracks through 180 degrees, then both tracks don't align again. The bridge has to be calibrated to align to the exit road, which is ok on my installation as I don't have any spurs opposite entry tracks.
It seems the track on the bridge is not true in my example.
I used some of the spare handrail that came with the turntable, and the other parts, ie., winding gear, vaccuum hose and locking levers ( not shown in pic) were from a Dapol turntable kit.