Hmmm looks likes either sunburn, or a magnesium deficiency. What's your watering and fertilizer routine?

Well, dog gone it. It could be both. I sat the pot from the porch into the sunlight about 9 days ago because I thought , "It being a large, broad leaf plant, it must need a lot of sun". I will put it back on the partially shaded porch. Secondly , I have not fertilized it yet because I felt the new potting mix, after re-potting this spring, would be sufficient for a good period of time. I will read and correct that also. Thank you for your input.

Well they love the sun for sure! But going from a shaded porch to full sun may have just shocked the leaves. I would leave it in the sun and keep it watered well and the new leaves will adapt to the sun.

Sunburn

Don't move it. Increase your watering. Sunburn IMO is a symptom of full sun and not enough water (but not to the point where the plant shows wilting).