My circadian cycle has been screwed for years. Even with militant reduction of device use, avoidance of caffeine, sugar or stimulants, for whatever reason, no matter how tired I am, I wake up fully around 9pm, feeling clear and generally “awake”. It’s hell. I did have success for a limited period of time by getting up at 4am and shifting my cycle from “late night” to “early morning”. It did feel better, but I was still out of sync with the 9-5 cycle which is by itself, completely out of sync with seasonal time. I don’t know about you, but the older I have become, the more sensitive I seem to be seasonal changes! I suppose once choice is to try early starts or late nights?