How can I correct inaccurate sleep data on Series 7 watch?

I recently bought my first Apple Watch, a Series 7. I've noticed that a couple of times a week, the sleep information isn't accurate. Last night, I woke up at 4:50 am, then laid in bed for a while, and the watch thinks I slept until 5:42, which is when I got out of bed.

I tried correcting the inaccurate data earlier this week by going into the Health app on my iPhone, clicking on Sleep, and using the Add Data button. But when I entered the correct information for Asleep > Ends, it didn't register as entered; weirdly, the bar graph now showed I was asleep in the late morning. (See Thursday entry in photo.)

What is the right way to correct sleep data registered by the Apple Watch? Thanks.