The answer to 'why is my skylight missing shingles' is that the shingles around the skylight have likely become damaged or worn over time, causing them to detach. This is a common issue with skylights, as the area around them is more exposed to the elements and can experience more wear and tear than the rest of the roof.
Some common causes of missing shingles around a skylight include: age and weathering of the shingles, improper installation or sealing of the skylight, and physical damage from debris or foot traffic. Symptoms may include water leaks, drafts, or visible gaps where the shingles are missing. To fix this issue, you may need to replace the damaged shingles, re-seal the skylight, or in some cases, replace the entire skylight assembly.