Had an architectural shingle roof installed by a reputable contractor a few months ago (on a brand new build) and now the valleys and shingles near the valleys are buckling. Shingles were installed in the winter at about the freezing mark so it's likely due to expansion. I have attached a couple of photos. It's a 7/12 pitch roof on a large bungalow (6500 square feet of roof area) ... the valleys are about 30 feet long. I'm assuming this is something to be concerned about ... what can be done to fix it?