The answer to 'why is my gutters curling shingles' is that improper gutter installation or maintenance can cause shingles to curl or lift at the edges. This is a common roofing problem that occurs when water from the gutters spills over the sides and gets under the shingles, causing them to warp and curl over time.
Some other common causes include poor ventilation in the attic, improper roof pitch, or using low-quality shingles. Curling shingles can lead to leaks, water damage, and other roofing issues if not addressed. In many cases, this problem requires professional repair or replacement of the gutters and affected shingles.