The answer to 'why is my soffit curling shingles' is that the soffit is likely not properly ventilated or insulated. Soffits that are not adequately ventilated can cause heat and moisture buildup, leading to the shingles curling and peeling away from the roofing structure. This is a common issue, especially in older homes or those with inadequate attic insulation.
To fix this problem, you may need to improve the ventilation in your soffits by adding vents or improving air circulation. You may also need to add insulation to the attic and ensure proper airflow between the attic and the soffit space. Addressing these underlying issues can help prevent further damage and restore the appearance of your roofing system.