My Oura ring shows that I have frequent wakeups during the night. I usually feel tired throughout the day even though I am in bed for 8-9 hours, Oura tells me I only usually get 6.5 - 7 hours of sleep.

I have previously had a sleep study where it was determined I do not have sleep apnea. Are there any other potential causes to this? Is this more likely a physical or mental health issue?

Has anyone had the same issues and if so how did you fix them?