Health App Calculates Sleep Trends Inaccurate

In the Health app, I’ve been routinely tracking the amount of sleep I’ve been getting by manually inputting the amount, using the sleep focus, and occasionally wearing my Apple Watch. I have an iPhone 15 Pro and an Apple Watch Series 9 and I’ve accumulated data for about 9 months. My concern is that despite having my 6M Avg. Time Asleep showing an accurate number, 7 hrs & 14 min., the Trend number is completely off showing 3 hrs & 18 min. I have no idea how it came to that calculation, but it’s annoying seeing a clearly inaccurate trend and telling me it’s gone down.