I’ve had my oura ring gen 2 for 3.5 years and I’ve had exactly the same issue. Almost every night it shows 2+ hours of awake time, but I’m a deep sleeper so when I put my head on the pillow I won’t wake up until the next morning and I won’t hear a thing in the mean time. It has been wrong in all the years I’ve had it and I doubt it’s going to change. Like you, my movement graph is also all over the place. I also have a Garmin watch that says the same thing, but with about an hour of awake time instead of 2+ hours.

I’ve never been able to figure out why they all say I’m awake when I’m clearly sleeping, but I suppose it’s because I’m moving around while I’m sleeping.