Help with early waking

Baby will be 6 months in a couple days and I’m really struggling with early wakes. This guy wakes 4-5am everyday. Ive tried feeds and back to bed, I’ve tried bedtimes ranging from 6am-8:30 and it doesn’t help. Tried a longer wake window at night and that didn’t help either. Room is pitch black as I live in a place where the sun doesn’t come up till 8:30am. He is sleep trained for nights and sleeps through but these early morning wakings are killing me especially when he only takes 30 mins naps. Schedule is loose depending when he wakes up so it’s unpredictable. Usually 2/2/2/3.5. Help please.