creating a discount based on certains product varients in the cart do not work for the guest checkout.
What do you mean by "based on certains product varients". Is your discount type set to 'Assigned to product variants'? Or your discount requement is set to one the following values: "Has all of these product variants in the cart", "Has one of these product variants in the cart", "Had purchased all of these product variants", "Had purchased one of these product variants"?