The answer to 'why is my fascia missing shingles' is that the fascia, which is the vertical board that runs along the edge of the roof, has likely lost its shingles due to weathering, damage, or poor installation. This can happen over time as the shingles on the fascia deteriorate from exposure to the elements, or if the fascia was not properly sealed and secured during the original roof installation.
Missing shingles on the fascia can allow moisture to penetrate the underlying wood, leading to rot and further damage. It's important to address this issue promptly to prevent more extensive and costly repairs down the line.