Dawn theme incorrect variant image showing

[piedyboy]

We are running Dawn Theme 6.02. We have multiple variants of some products. If you click through the different colours of the variants after a couple of clicks the wrong variant image is displayed. Even if there are only 2 colour options. Once you have clicked on them once the next click shows up the incorrect colour.

The correct images are assigned to the variants in the product editor

I see this has been a problem for others but there are no relevent answers after searching the community