Whats causing this?

Hard to guess which insects are attacking it, could be multiple, the only thing I can say isn't eating it is slugs or snails, they are what I have problems with and the damage they do isn't like yours. It's so hard outside to stop insect attacks.

Slug?

Hi Grower, It seems to me that your dealing with the outside life: Chewing insect damage: the holes in the leaves could also be caused by caterpillars, beetles, or other insects that feed on plant tissue. Chemical damage or burn to the growing tips: for example, from an overly strong foliar spray or a product that came into contact with the young shoots. What I notice in this photo: The older leaves appear to be mostly healthy. The newest leaves are distorted and show yellow/brown damage with holes, which points more toward a pest issue rather than a nutrient deficiency.