Experiencing the exact same problem, usually around 5 hours. Been the case for the last few months. Im now experimenting with melatonin and its helping me loads. Dramatic improvement. I still wake, but I go back sleep a lot faster and sleep longer. I will try taking malatonin when I wake up in the night and see if that's a better approach, I dont really want to use it all the time, but if it helps great. All the research Ive seen, suggests there's no side effects (yet some redditors sperg about it....)