What helps me is no caffeine after 12 (noon) and being ok with only starting work at 10, or working from home on random days where I had trouble falling asleep

What helps me is no caffeine after 12 (noon) and being ok with only starting work at 10, or working from home on random days where I had trouble falling asleep the night before. Of course not everybody has that luxury. I have always been a night owl and don’t wake up early usually. Like many other people with ADHD once I’m asleep I am very hard to wake. So my problem has always been falling asleep, not staying asleep. It sounds like your natural sleep habits are a bit different so I’m not sure what to suggest. Maybe try taking naps? I also wonder if maybe the rest of the world waking up (like the garbage truck coming, street cleaners, etc.) are waking you up at that specific time.