After some googling this seems to be an issue that is not uncommon. Basically the left cleat / pedal is clicking.
The pedal and the cleat are brand new so there is not an issue due to wear.
Increasing the tension makes no difference but some dry lubricant spray stops it for a bit.
I have adjusted the angle of the cleat so that they are the same as they would be for normal spds incase there was twisting going on during the stroke but that does not seem to have solved the issue.
Has anyone else had these woes and solved them?