Paul, I've the exact same configuration machine and it was used to develop Dokan, I am not seeing it. Although when I refresh the page the page looks like your screenshot, but when it's fully loaded, it becomes stable. I am not seeing any pointers what might be causing it.
Would you please check your Product Image Sizes in Woocommerce settings tab? Please navigate to Woocommerce–>Settings–>Products–>Product Image Sizes then Product Thumbnails and change the size then delete the cache and visit homepage. I think it can solve this issue. Thank you..