Shopify sets a variant limit per product of 100 variants. With SPOD’s products, 1 colour in 1 size is a variant. For example a Men's T-Shirt, in black and in size small is 1 variant.
So, there are products if you activate all the colors, it exceeds the 100 variant limit. This will result in some missing sizes from your store front. These tend to be the larger sizes.
To avoid this issue, we recommend creating a product with a maximum of 12 colors.
If you would like to have a certain product available in more than 12 colors, please create the product again in the extra colors.