Possible reasons:
1)Inaccurate positioning: Occasionally, inaccurate positioning may result in missed mowing. In future schedules, mow the area multiple times to cover any missed sections
2)Tall grass: If the grass length exceeds 6 inches, the area may be recognized as an obstacle, and the machine might avoid it.
3) Obstacles: Occasionally, sudden obstacles may appear in the garden. If such obstacles are temporary, the machine will cover the uncut areas during the next scheduled operation.