Doesn't look like a fungus. How do the vines look. Are there any pests under the leaves or borers in the vines?

The vines all look fine and I can't see any pests either. I do have a few slugs but they haven't been bothering them much this year. Could it be a potassium deficiency?? I have been fertilizing every few weeks but it wasn't very high in potassium.

Oh and the hole in the leaf is just from the hail we had a few weeks ago. Could that have stressed the plant??