Woocommerce – Attributes not being saved

I am doing a clothing website using Elegant Themes Divi theme with Woocommerce bundled with it.

I have all my products loaded and have set two attributes for size and colour.

For each product I select “Attributes” and add the two attributes.
Then I save the attribute, then update the product and the page.

When I view the product the attributes do not appear.

When I go back into the product and attribute selection both selected attributes have disappeared. I have tried re-selectimg them but every time I go back they are not there.

Does anyone have any idea as to why?