Changes in raid spawns in the early morning

just curious has anyone noticed that in the early parts of each day most raids are 1-3 star (6am-9am) and legendary raids don’t start until a few hours later? I’m an early morning player due to work and in the past month I can hardly ever get a legendary raid in the early morning because they don’t exist compared to the past. I play in a big city and travel a lot and it’s definitely changed